Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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REMOVABLE ROUNDED VIIDSOLE STRUCTURES
AND CHAMBERS 'VITH COMPUTER PROCESSOR-
CO\'TROLLED VARIABLE PRESSURE
BACKGROUND OF THE I\'VENTIOiVT
1. Field of the Invention
This invention relates Generally to footwear such as a shoe, including an
athletic shoe, with a shoe sole. including at least one non-orthotic removable
insert formed by a midsole portion. The removable midsole portion is inserted
into the foot opening of the shoe upper, the sides of which hold it in
position, as
may the bottom sole or other portion of the midsole. The shoe sole includes a
concavely rounded side or underneath portion, which may be formed in part by
the removable midsole portion. The removable midsole portion may extend the
len~ h of the shoe sole or may form only a part of the shoe sole and can
1 o incorporate cushioning or structural compartments or components. The
removable midsole portion provides the capability to permit replacement of
midsole material which has degraded or has worn out in order to maintain
optimal
characteristics of the shoe sole. Also, the removable midsole portion allows
customization for the individual wearer to provide tailored cushioning or
support
1 ~ characteristics.
The invention further relates to a shoe sole which includes at least one
non-orthotic removable midsole insert, at least one chamber or compartment
containing a fluid. a flow regulator, a pressure sensor to monitor the
compartment
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7
pressure. and a control system capable of automatically adjusting the pressure
in
the chamber or compartments) in response to the impact of the shoe sole with
the
ground surface, including embodiments which accomplish this function through
the use of a computer such as a microprocessor.
2. Brief Description of the Prior Art
Many existing athletic shoes are unnecessarily unsafe. Many existing
shoe designs seriously impair or disrupt natural human biomechanics. The
resulting unnatural foot and ankle motion caused by such shoe designs leads to
o abnormally high levels of athletic injuries.
Proof of the unnatural effect of many existing shoe designs has come
quite unexpectedly from the discovery that, at the extreme end of its normal
range
of motion, the unshod bare foot is naturally stable and almost impossible to
sprain, while a foot shod with a conventional shoe, athletic or otherW se, is
artificially unstable and abnormally prone to ankle sprains. Consequently,
most
ordinary ankle sprains must be viewed as largely an unnatural phenomena, even
though such ankle sprains are fairly common. Compelling evidence demonstrates
that the stability of bare feet is entirely different from, and far superior
to, the
stability of shod feet.
2 o The underlying cause of the nearly universal instability of shoes is a
critical but correctable design flaw. That hidden flaw, so deeply ingrained in
existing shoe designs, is so extraordinarily fundamental that it has remained
unnoticed until now. The flaw is revealed by a novel biomechanical test, ene
that
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may be unprecedented in its extreme simplicity. The test simulates a lateral
ankle
sprain while standing stationary . It is easily duplicated and may be
independently
verified by anyone in a minute or tvvo without any special equipment or
expertise.
The simplicity of the test belies its surprisingly convincing results. It
demonstrates an obvious difference in stability between a bare foot and a foot
shod with an athletic shoe, a difference so unexpectedly noticeable that the
test
proves beyond doubt that many existing shoes are unstable and thus unsafe.
The broader implications of this discovery are potentially far-reaching.
The same fundamental flaw in existing shoes that is glaringly exposed by the
new
test also appears to be the major cause of chronic overuse injuries, which are
unusually common in running, as well as other chronic sport injuries. Existing
shoe designs cause the chronic injuries in the same w-ay they cause ankle
sprains;
that is, by seriously disrupting natural foot and ankle biomechanics.
The applicant has introduced into the art the concept of a theoretically
ideal stability plane as a structural basis for shoe sole designs. That
concept, as
implemented into shoes such as street shoes and athletic shoes, is presented
in
U.S. Patent Nos. 4,989,349, issued on February 5, 1991; x,317,819, issued on
June 7, 1994; and ~,~44,429, issued on August 13, 1996, as well as in PCT
Application No. PCT/LJS89/03076 filed on July 14, 1989, and many subsequent
2e U.S. and PCT applications.
The purpose of the theoretically ideal stability plane as described in these
applications is primarily to provide a neutral shoe desist that allows for
natural
foot and ankle biomechanics without the serious interference from the shoe
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4
design that is inherent in many existing shoes.
Accordingly, it is a general object of one or more embodiments of the
invention to elaborate upon the application of the principle of the natural
basis for
the support, stability and cushioning of the bare foot to shoe designs.
It is still another object of one or more embodiments of the invention to
provide a shoe having a sole with natural stability which puts the side of the
shoe
upper under tension in reaction to destabilizing sideways forces on a tilting
shoe.
It is still another object of one or more embodiments of the invention to
balance the tension force on the side of the shoe upper substantially in
to equilibrium to neutralize the destabilizing sideways motion by virtue of
the
tension in the sides of the shoe upper.
It is another object of one or more embodiments of the invention to create
a shoe sole with support and cushioning which is provided by shoe sole
compartments, filled with a pressure-transmitting medium like liquid, gas, or
gel,
1 s that are similar in structure to the fat pads of the foot. and which
simultaneously
provide both firm support and progressive cushioning.
A further object of one or more embodiments of the invention is to
elaborate upon the application of the principle of the theoretically ideal
stability
plane to other shoe structures.
2 o A still further object of one or more embodiments of the invention is to
provide a shoe having a sole contour which deviates in a constructive way from
the theoretically ideal stability plane.
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A still further object of one or more embodiments of the invention is to
provide a sole contour having a shape naturally rounded to the shape of a
human
foot, but having a shoe sole thickness which is increased somewhat beyond the
thickness specified by the theoretically ideal stability plane, either through
most
of the contour of the sole, or at pre-selected portions of the sole.
It is yet another object of one or more embodiments of the invention to
provide a naturally rounded shoe sole having a thickness which approximates a
theoretically ideal stability plane, but which varies toward either a greater
or
lesser thickness throughout the sole or at pre-selected portions thereof.
? o It is another object of one or more embodiments of the present invention
to implement one or more of the foregoing objects by employing a non-orthotic
removable midsole portion of the shoe.
It is yet another object of one or more embodiments of the present
invention to combine one or more of the foregoing objects with the ability to
1 s customize the shoe design for a particular wearer's foot.
It is a still further object of one or more embodiments of the present
invention to combine one or more of the foregoing objects with the ability to
replace one or more portions of the shoe in order to substitute new portions
for
worn portions or for the purpose of customizing the shoe design for a
particular
2 c activity.
These and other objects of the invention will become apparent from the
summary and detailed description of the invention which follow, taken with the
accompanying drawings.
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SUVTNIARY OF THE INVENTION
In one aspect, the present invention attempts. as closely as possible, to
replicate the naturally effective structures of the bare foot that provide
stability,
support, and cushioning. More specifically, the invention relates to the
structure
of removable midsole inserts formed from a midsole portion and integrated into
shoes such as athletic shoes. The removable midsole inserts of the present
invention are non-orthotic. Even more specifically, this invention relates to
the
provision of a shoe having an anthropomorphic sole including a non-orthotic
1 o midsole insert that substantially copies features of the underlying
support,
stability and cushioning structures of the human foot. Natural stability is
provided by balancing the tension force on the side of the upper in
substantial
equilibrium so that destabilizing sideways motion is neutralized by the
tension.
Still more particularly, this invention relates to support and cushioning
which is provided by shoe sole compartments filled W th a pressure-
transmitting
medium like liquid, gas. or gel. Unlike similar existing systems, direct
physical
contact occurs between the upper surface and the lower surface of the
compartments, providing firm, stable support. Cushioning is provided by the
pressure-transmitting medium progressively causing tension in the flexible and
2 o semi-elastic sides of the shoe sole. The compartments providing support
and
cushioning are similar in structure to the fat pads of the foot, which
simultaneously provide both firm support and progressive cushioning.
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Directed to achieving the aforementioned objects and to overcoming
problems with prior art shoes, a shoe according to one or more embodiments of
the invention comprises a sole having at least a portion thereof which is
naturally
rounded whereby the upper surface of the sole does not provide a substantial
unsupported portion that creates a destabilizing torque and the bottom surface
does not provide a substantial unnatural pivoting edge.
In another aspect of the invention, the shoe includes a naturally rounded
sole structure exhibiting natural deformation which closely parallels the
natural
deformation of a foot under the same load. The shoe sole is naturally rounded,
paralleling the shape of the foot in order to parallel its natural
deformation, and
made from a material which, when under load and tilting to the side, deforms
in a
manner which closely parallels that of the foot of its wearer, while retaining
nearly the same amount of contact of the shoe sole with the ground as in its
upright state under load.
i 5 In another aspect, one or more embodiments of this invention relate to
variations in the structure of such shoes having a sole contour which follows
a
theoretically ideal stability plane as a basic concept, but which deviates
therefrom
to provide localized variations in natural stability. This aspect of the
invention
may be employed to provide variations in natural stability for an individual
whose
2 o natural foot and ankle biomechanical functioning have been degraded by a
lifetime use of flawed existing shoes.
This new invention is a modification of the inventions disclosed and
claimed in the applicant's previously mentioned prior patent applications and
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develops the application of the concepts disclosed therein to other shoe
structures.
In this respect, one or more of the features and/or concepts disclosed in the
applicant's prior applications may be implemented in the present invention by
the
provision of a non-orthotic removable midsole portion. Alternatively, one or
more of the features and/or concepts of the present invention may be combined
with the provision of a removable midsole portion which itself may or may not
implement one of the concepts disclosed in the applicant's prior applications.
Further, the removable midsole portion of the present invention may be
provided
as a replacement for worn shoe portions and/or to customize the shoe design
for a
1 o particular wearer, for a particular activity or both and, as such, may
also be
combined with one or more of the features or concepts disclosed in applicant's
prior applications.
These and other features of the invention will become apparent from the
detailed description of the invention which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1-10 and 12-7~ represent embodiments similar to those disclosed in
applicant's issued U.S. patents and previous applications. F jaure 11
illustrates
aspects of the concavely rounded removable midsole insert and chambers or
2 o bladders with microprocessor controlled variable pressure of the present
mventton.
Fig. 1 is a perspective view of a prior art conventional athletic shoe to
which the present invention is applicable.
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Fig. 2 illustrates in a close-up frontal plane cross section of the heel at
the
ankle joint the typical shoe known in the art, which does not deform as a
result of
body weight, when tilted sideways on the bottom edge.
Fig. 3 shows, in the same close-up cross section as Fig. 2, a naturally
rounded shoe sole design, also tilted sideways.
Fig. 4 shows a rear view of a barefoot heel tilted laterally 20 degrees.
Fig. ~ shows, in a frontal plane cross section at the ankle joint area of the
heel, tension stabilized sides applied to a naturally rounded shoe sole.
Fig. 6 shows, in a frontal plane cross section, the Fig. ~ design when tilted
i o to its edge, but undeformed by load.
Fig. 7 shows, in frontal plane cross section at the ankle joint area of the
heel, the Fig. ~ design when tilted to its edge and naturally deformed by body
weight.
Fig. 8 is a sequential series of frontal plane cross sections of the barefoot
heel at the ankle joint area.
Fig. 8A is an unloaded and upright barefoot heel.
Fig. 8B is a heel moderately loaded by full body weight and upright.
Fig. 8C is a heavily loaded heel at peak landing force while running and
upright.
2 o Fig. 8D is heavily loaded heel shown tilted out laterally by about 20
degrees, the maximum tilt for the heel.
Fig. 9 shows a sequential series of frontal plane cross sections of a shoe
sole design of the heel at the ankle joint area that corresponds exactly to
the Fig. 8
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series described above.
Fig. 10 shows nvo perspective views and a close-up view of a part of a
shoe sole with a structure like the fibrous connective tissue of the groups of
fat
cells of the human heel.
Fig. l0A shows a quartered section of a shoe sole with a structure
comprising elements corresponding to the calcaneus with fat pad chambers below
it.
Fig. 1 OB shows a horizontal plane close-up of the inner structures of an
individual chamber of a shoe sole.
1 o Fig. l OC shows a horizontal section of a shoe sole with a structure
corresponding to the whorl arrangement of fat pad underneath the calcaneus.
Figs. 1 lA-11C are frontal plane cross-sectional views showing three
different variations of removable midsole inserts in accordance with the
present
invention.
1 ~ Fig. 11 D is an exploded view of an embodiment of a removable midsole
in accordance with the present invention.
Figs. 11E-11F are cross-sectional views of alternative embodiments of
interlocking interfaces for releasably securing the removable midsole of the
present invention.
2 o Fig. 11 G is a frontal plane cross-section of a removable midsole formed
with asymmetric side height. Figs. 11H-11J show other frontal plane sections.
Fig. 11K shows a sagittal plane section and Fig. 11L shows a horizontal plane
top
mew.
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Fig. 111vI-11 O are frontal plane cross-sectional views showing three
variations of midsole inserts with one or more pressure controlled
encapsulated
midsole sections and a control system such as a microprocessor.
Fig. 11P is an exploded view of an embodiment of a removable midsole
with pressure controlled encapsulated midsole sections and a control system
such
as a microprocessor.
Figs. 12A-12C show a series of conventional shoe sole cross sections in
the frontal plane at the heel utilizing both sagittal plane and horizontal
plane
sipes, and in which some or all of the sipes do not originate from any outer
shoe
sole surface, but rather are entirely internal
Fig. 12D shows a similar approach as is shown in Figs. 12A-12C applied
to the fully rounded design.
Figs. 13A-13B show, in frontal plane cross section at the heel area, shoe
sole structures similar to those shown in Figs. ~A-B, but in more detail and
with
i 5 the bottom sole extending relatively farther up the side of the midsole.
Fig. 14 shows, in frontal plane cross section at the heel portion of a shoe,
a shoe sole with naturally rounded sides based on a theoretically ideal
stability
plane.
Fig. 1 S shows, in frontal plane cross section, the most general case of a
2 o fully rounded shoe sole that follows the natural contour of the bottom of
the foot
as well as its sides, also based on the theoretically ideal stability plane.
Figs. 16A-16C show, in frontal plane cross section at the heel, a quadrant-
sided shoe sole, based on a theoretically ideal stability plane.
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Fig. 17 shows a frontal plane cross section at the heel portion of a shoe
with naW rally rounded sides like those of Fig. 14, wherein a portion of the
shoe
sole thickness is increased beyond the theoretically ideal stability plane.
Fig. 18 is a view similar to Fig. 17, but of a shoe with fully rounded sides
wherein the sole thickness increases with increasing distance from the center
line
of the ground-contacting portion of the sole.
Fig. 19 is a view similar to Fig. 18 where the fully rounded sole thickness
variations are continually increasing on each side.
Fig. 20 is a view similar to Figs. 17-19 wherein the sole thickness varies
o in diverse sequences.
Fig. 21 is a frontal plane cross section showing a density variation in the
midsole.
Fig. 22 is a view similar to Fia. 21 wherein the firmest density material is
at the outermost edge of the midsole contour.
15 Fig. 23 is a view similar to Figs. 21 and 22 showing still another density
variation, one which is asymmetrical.
Fig. 24 shows a variation in the thickness of the sole for the quadrant-
sided shoe sole embodiment of Figs. 16A-16C which is greater than a
theoretically ideal stability plane.
2 o Fig. 25 shows a quadrant-sided embodiment as in Fig. 24 wherein the
density of the sole varies.
Fig. 26 shows a bottom sole tread design that provides a similar density
variation to that shown in Fig. 23.
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Fig. 27 shows embodiments similar to those shown in Fias. 1=1-16, but
wherein a portion of the shoe sole thickness is decreased to less than the
theoretically ideal stability plane.
Fig. 28 shows embodiments of the invention writh shoe sole sides having
thickness' both greater and lesser than the theoretically ideal stability
plane.
Fig. 29 is a frontal plane cross-section showing a shoe sole of uniform
thickness that conforms to the natural shape of the human foot.
Figs. 30A-30D show a load-bearing flat component of a shoe sole and a
naturally rounded side component, as well as a preferred horizontal periphery
of
1 ~ the flat load-bearing portion of the shoe sole.
Figs. 31A-31B are diagrammatic sketches showing a rounded side sole
design according to the invention with variable heel lift.
Fig. 32 is a side view of a stable rounded shoe according to the invention.
Fig. 33A is a cross-sectional view of the forefoot portion of a shoe sole
15 taken along lines 33A of Figs. 32 and 33D.
Fig. 33B is a cross-sectional view taken along lines 33B of Figs. 32 and
33D.
Fig. 33C is a cross-sectional view of the heel portion taken along lines
33C in Figs. 32 and 33D.
2 o Fig. 33D is a top view of the shoe sole shown in Fig. 32
Figs. 34A-34D are frontal plane cross-sectional views of a shoe sole
according to the invention showing a theoretically ideal stability plane and
truncations of the sole side contour to reduce shoe bulk.
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Figs. 3~A-3~C show a rounded sole design according to the invention
when applied to various tread and cleat patterns.
Fig. 36 is a diagrammatic frontal plane cross-sectional view of static
forces acting on the ankle joint and its position relative to a shoe sole
according to
the invention during normal and extreme inversion and eversion motion.
Fig. 37 is a diagrammatic frontal plane view of a plurality of moment
curves of the center of gravity for various degrees of inversion for a shoe
sole
according to the invention contrasted with comparable motions of conventional
shoes.
Fig. 38 shows a design with naturally rounded sides extended to other
structural contours underneath the load-bearing foot such as the main
longitudinal
arch.
Fig. 39 illustrates a fully rounded shoe sole design extended to the bottom
of the entire non-load bearing foot.
15 Fig. 40 shows a fully rounded shoe sole design abbreviated along the sides
to only essential structural support and propulsion elements.
Fig. 41 illustrates a street shoe with a correctly rounded sole according to
the invention and side edges perpendicular to the ground.
Fig. 42 shows several embodiments wherein the bottom sole includes
2 o most or all of the special contours of the designs and retains a flat
upper surface.
Fig. 43 is a rear view of a heel of a foot for explaining the use of a
stationery sprain simulation test.
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l~
Fig. 44 is a rear view of a conventional athletic shoe unstably rotating
about an edge of its sole when the shoe sole is tilted to the outside.
Figs. 4~A-4~C illustrate functionally the principles of natural deformation
as applied to the shoe soles of the invention.
Fig. 46 shows variations in the relative density of the shoe sole including
the shoe insole to maximize an ability of the sole to deform naturally.
Fig. 47 shows a shoe having naturally rounded sides bent inwardly from a
conventional design so then when worn the shoe approximates a custom fit.
Fig. 48 shows a shoe sole having a fully rounded design but having sides
which are abbreviated to the essential structural stability and propulsion
elements
and are combined and integrated into discontinuous structural elements
underneath the foot that simulate those of the foot.
Fig. 49 shows the theoretically ideal stability plane concept applied to a
negative heel shoe sole that is less thick in the heel area than in the rest
of the
s shoe sole, such as a shoe sole comprising a forefoot lift.
Fig. 49A is a cross sectional view of the forefoot portion taken along line
49A of Fig. 49D.
Fig. 49B is a view taken along line 49B of Fig. 49D.
Fig. 49C is a view of the heel along line 49C of Fig. 49D.
2 o Fig. 49D is a top view of the shoe sole with a thicker forefoot section
shown with cross-hatching.
Figs. BOA-SOE show a plurality of side sagittal plane cross sectional views
of examples of negative heel sole thickness variations (forefoot lift) to
which the
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general approach shown in Fias. 49A-49D can be applied.
Fig. ~ 1 shows the use of the theoretically ideal stabilit'~ plane concept
applied to a flat shoe sole with no heel lift by maintaining the same
thickness
throughout and providing the shoe sole with rounded stability sides
abbreviated to
only essential structural support elements.
Fig. 51 A is a cross sectional view of the forefoot portion taken along line
~lA of Fig. ~1D.
Fig. ~ 1 B is a view taken along line ~ 1 B of Fig. ~ 1 D.
Fig. ~ 1 C is a view taken along the heel along line ~ 1 C in Fig. ~ 1 D.
Fig. S 1 D is a top view of the shoe sole with sides that are abbreviated to
essential structural support elements shown hatched.
Fig. ~ lE is a sagittal plane cross section of the shoe sole of Fia. ~ 1 D.
Fig. 52 shows, in frontal plane cross section at the heel, the use of a high
density (d') midsole material on the naturally rounded sides and a low density
(d)
15 midsole material everywhere else to reduce side width.
Fig. 53 shows the footprints of the natural barefoot sole and shoe sole.
Fig. 53A shows the foot upright with its sole flat on the ground.
Fig. 53B shows the foot tilted out 20 degrees to about its normal limit.
Fig. 53C shows a shoe sole of the same size when tilted out 20 decrees to
2o the same position as Fig ~3B. The right foot and shoe are shown.
Fig. ~4 shows footprints like those shown in Figs. 53A and 53B of a right
bare foot upright and tilted out 20 degrees, but showing also their actual
relative
positions to each other as a high arched foot rolls outward from upright to
tilted
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out 20 de~-rees.
Fig. » shows a shoe sole with a lateral stabiliy sipe in the form of a
vertical slit.
Fig. ~~A is a top view of a conventional shoe sole with a corresponding
outline of the wearer's footprint superimposed on it to identify the position
of the
lateral stability sipe relative to the wearer's foot.
Fig. ~~B is a cross section of the shoe sole with lateral stability sipe.
Fig. ~6C is a top view- like Fig. ~~A, but shoal ng the print of the shoe
sole with a lateral stability sipe when it is tilted ourivard 20 degrees.
Fig. ~6 shows a medial stability sipe that is analogous to the lateral sipe,
but to provide increased pronation stability. The head of the first metatarsal
and
the first phalange are included with the heel to form a medial support
section.
Fig. ~7 shows footprints 37 and 17, like Fig. ~-I, of a right bare foot
upright and tilted out 20 degrees, showing the actual relative positions to
each
s other as a low arched foot rolls outward from upright to tilted out 20
degrees.
Fig. ~8A-D show the use of flexible and relatively inelastic fiber in the
form of strands, woven or unwoven (such as pressed sheets), embedded in
midsole and bottom sole material.
Fig. ~9A-D show the use of flexible inelastic fiber or fiber strands, woven
20 or unwoven (such as pressed) to make an embedded capsule shell that
surrounds
the cushioning compartment 161 containing a pressure-transmitting medium like
gas, gel, or liquid.
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Fig. 60A-D show the use of embedded tleYible inelastic fiber or fiber
strands, woven or unwoven, in various embodiments similar those shown in Figs.
~ 8A-D.
Fig. 60E shows a frontal plane cross section of a fibrous capsule shell 191
that directly envelopes the surface of the midsole section 188.
Fig. 61 shows a view of a bottom sole structure 149, but with no side
sections.
Fig. 62 shows a similar structure to Fig. 61, but with only the section
under the forefoot 126 unglued or not firmly attached, the rest of the bottom
sole
149 (or most of it) would be glued or firmly attached
Fig. 63C compares the footprint made by a conventional shoe 3~ with the
relative positions of the wearer's right foot sole in the maximum supination
position 37a and the maximum pronation position 37b.
Fig. 63D shows an overhead perspective of the actual bone structures of
:, the foot that are indicated in Fig. 63C.
Fig. 64 shows on the right side an upper shoe sole surface of the rounded
side that is complementary to the shape of the wearer's foot sole; on the left
side
Fig. 64 shows an upper surface between complementary and parallel to the flat
ground and a lower surface of the rounded shoe sole side that is not in
contact
2 o with the ground.
Fig. 6~ indicates the angular measurements of the rounded shoe sole sides
from zero degrees to 180 degrees.
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Fia. 66 shows a shoe sole without rounded stabilin~ sides.
Figs. 67-68 also shows a shoe sole without rounded stability sides.
Figs. 69A-E show the implications of relative difference in range of
motions bet'veen forefoot, Midtarsal, and heel areas on the applicant's
naturally
.. rounded sides invention.
Fig. 70 shows an invention for a shoe sole that covers the full range of
motion of the wearer's right foot sole.
Fig. 71 shows an electronic image of the relative forces present at the
different areas of the bare foot sole when at the maximum supination position
shown as 37a in Fig. 62; the forces were measured during a standing simulation
of the most common ankle spraining position.
Figs. 72G-H show shoe soles with only one or more of the essential
stability elements, but which, based on Fig. 71, still represent major
stabiliy.~
improvements over existing footwear. All omit changes in the heel area.
i s Fig. 72G shows a shoe sole combining additional stability corrections 96a,
96b, and 98, supporting the first and fifth metatarsal heads and distal
phalange
heads.
Fig. 72H shows a shoe sole with symmetrical stability additions 96a and
96b.
2o Figs. 73A-73D show in close-up sections of the shoe sole various new
forms of sipes, including both slits and channels.
Fig. 74 shows, in Figs. 74A-74E, a plurality of side sagittal plane cross-
sectional views showing examples of variations in heel lift thickness similar
to
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those shown in Figs. BOA-E for the forefoot lift.
Fig. 7~ shows, in Figs. 7~A-7~C, a method, known from the prior art, for
assembling the midsole shoe sole structure of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to the provision of a removable midsole
insert or a removable midsole portion in a shoe sole. The removable midsole
concept of the present invention is described more fully with reference to
Figs.
11 A-I 1 P below. The removable midsole or removable midsole sections of the
o present invention are non-orthotic. The term "non-orthotic" means that the
removable midsoles or midsole portions are not corrective, therapeutic,
prosthetic, nor are they prescribed by health care professionals.
The removable midsole or midsole portion. can be used in combination
with, or to replace, any one or more features of the applicant's prior
inventions
15 as shown in the figures of this application. Such use of the removable
midsole
or midsole portion can also include a combination of features shown in any
other figures of the present application. For example, the removable midsole
of
the present invention may replace all or any portion or portions of the
various
midsoles, insoles and bottom soles which are shown in the figures of the
2 o present application, and may be combined with, or used to implement, one
or
more of the various other features described in reference to any of these
figures
in any of these forms.
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All reference numerals used in the figures contained herein are defined
as follows:
Ref. No. Element Descri tion
2 insole
3 attachment oint of a er midsole and shoe a er
4 attachment oint of bottom sole and shoe a er
attachment oint of bottom sole and a er midsole
6 attachment oint of bottom sole and lower midsole
8 lower surface interface with the a er surface of
the bottom sole
9 interface line between enca sulated section and
midsole ortions
11 lateral stability si a
12 medial stability si a
13 interface between insole and shoe a er
14 medial origin of the lateral stability si a
16 hatched area of decreased area of foot Tint due
to ronation
17 foo Tint outline when tilted
18 inner foo rint outline of low arched foot
19 hatched area of increased area of foot rint due
to ronation
20 athletic shoe
21 shoe a er
22 conventional shoe sole
23 bottom outside edge of the shoe sole
23a lever arm
26 stabilizing uadrants
27 human foot
28 rounded shoe sole
28a rounded stabili sides
28b load bearing shoe sole
29 outer surface of the foot
30 a er surface of the shoe sole
30a side or inner edge of the shoe sole stabili r side
30b a er shoe sole surface which contacts the wearer's
foot
31 lower surface of the shoe sole
31 a outer edge of rounded stability sides
31b lower surface of shoe sole arallel to 30b
32 outside and to edge of the stability side
33 inner ed a of the naturally rounded stabili side
34 a endicular sides of the load-bearing shoe sole
3~ eri heral extent of the a er surface of sole
36 shoe sole outline
37 foot outline
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37a maximum su ination osition
37b maximum ronation osition
38 heel lift
39 combined midsole and bottom sole
forefoot lift
13 ground
~ 1 theoretically ideal stability lane
~ 1' half of the theoretically ideal stability lane
~3a to of rounded stability side
60 tread onion
61 cleated ortion
62 alternative tread construction
63 surface which the cleat bases are affixed
70 curve of ran~e of side to side motion
71 center of gravity
80 conventional wide heel flare curve
82 narrow rectangle the width of heel curie
8~ contour line of areas of shoe sole that are in
contact wzth the ound
86 contour line
86 contour line
87 contour line
88 contour line
89 contour line
92 head of first metatarsal
93 head of fifth distal halanae
94 head of fifth metatarsal
9> base and lateral tuberosity of the calcaneus
96 heads of the metatarsals
96a stability correction su ortina fifth metatarsal
and distal halanae heads
96b stabili correction su ortina first metatarsal and
distal halanae heads
97 base of the fifth metatarsal
98 head of the first distal halange
98a stabili correction su ortina first distal halanae
98a' stability correction su ortina fifth distal halanae
100 straight line re lacing indentation at the base
of the fifth metatarsal
104 ressure sensing device
108 lateral calcaneal tuberosity
109 main base of the calcaneus
111 flexibility axis
112 flexibility axis
113 flexibili axis
11 ~ center of rotation of radius r + r'
119 center of shoe sole su ort section
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23
120 ressure sensing circuim
_
121 main longitudinal arch (long arch)
122 flexibility axis
123 flexible connecting to layer of si es
124 flexibility axis
12~ base of the calcaneus (heel)
126 metatarsal heads (forefoot)
129 honeycombed ortion
14~ non-orthotic removable midsole section
147 a er midsole (u er areas of shoe midsole)
148 midsole
149 bottom sole
1 ~0 com ression force
1 ~ 1 channels with arallel side walls
1 a tension force along the to surface of the shoe
sole
1 ~~b mirror image of tension force 1 ~~a
1~8 subcalcaneal fat ad
1~9 calcaneus
160 bottom sole of the foot
161 cushioning com artment
162 natural crease or a ward to er
163 crease or to er in the human foot
164 chambers of matrix of elastic fibrous connectivetissue
16~ lower surface of the a er midsole
166 a er surface of the bottom sole
167 outer surface of the su ort structures of the foot
168 a er surface of the foot's bottom sole
169 shank
170 flexible material filling channels (si es)
180 mini-chambers
181 internal deformation slits (si es) in the saQittal
lane
182 internal deformation slits (si es) in the horizontal
lane
184 enca sulating outer midsole section
18~ midsole sides
187 a er midsole section
188 enca sulated midsole section or bladder
189 central wall
191 fibrous ca sule shell
192 subdivided cushioning com artments
201 horizontal line through lower most oint of a er
surface of the shoe sole
206 fluid duct
210 fluid valve
300 control s stem
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Fig. 1 shows a perspective view of a shoe. such as a typical athletic shoe
according to the prior art. wherein the athletic shoe 20 includes an upper
portion
21 and a sole 22.
.. Fia. 2 illustrates, in a close-up, a cross-section of a typical shoe of
existing
art (undeformed by body weight) on the ground 43 when tilted on the bottom
outside edge 23 of the shoe sole 22, that an inherent stability problem
remains in
existing shoe designs, even when the abnormal torque producing rigid heel
counter and other motion devices are removed. The problem is that the
remaining
shoe upper 21 (shown in the thickened and darkened line), while providing no
lever arm extension, since it is flexible instead of rigid. nonetheless
creates
unnatural destabilizing torque on the shoe sole. The torque is due to the
tension
force 1 ~~a along the top surface of the shoe sole 22 caused by a compression
force 1 ~0 (a composite of the force of gravity on the body and a sideways
motion
1 s force) to the side by the foot 27, due simply to the shoe being tilted to
the side, for
example. The resulting destabilizing force acts to pull the shoe sole in
rotation
around a lever arm 23a that is the width of the shoe sole at the edge. Roughly
speaking, the force of the foot on the shoe upper pulls the shoe over on its
side
when the shoe is tilted sideways. The compression force 150 also creates a
2o tension force 1~5b, which is the mirror image oftension force 15~a.
Fig. 3 shows, in a close-up cross section of a naturally rounded design of
rounded shoe sole 28 (also shown undeformed by body weight) when tilted on the
bottom edge, that the same inherent stability problem remains in the naturally
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rounded shoe sole design, though to a reduced degree. The problem is less
since
the direction of the force vector 1 ~0 along the lower surface of the shoe
upper 21
is parallel to the ground 43 at the outer sole edge 32 edge, instead of angled
toward the ground as in a conventional design like that shown in Fig. ?, so
the
resulting torque produced by a lever arm created by the outer sole edge 32
would
be less, and the rounded shoe sole 28 provides direct structural support when
tilted, unlike conventional designs.
Fig. =1 shows (in a rear view) that, in contrast, the bare foot is naturally
stable because, when deformed by body weight and tilted to its natural lateral
limit of about 20 degrees, it does not create any destabilizing torque due to
tension force. Even though tension paralleling that on the shoe upper is
created
on the outer surface 29, both the bottom and sides, of the bare foot by the
compression force of weight-bearing, no destabilizing torque is created
because
the lower surface under tension (i.e. the foot's bottom sole, shown in the
darkened
line) is resting directly in contact with the ground. Consequently, there is
no
unnatural lever arm artificially created against which to pull. The weight of
the
body firmly anchors the outer surface of the sole underneath the foot so that
even
considerable pressure against the outer surface 29 of the side of the foot
results in
no destabilizing motion. When the foot is tilted, the supporting stmctures of
the
2 o foot. like the calcaneus, slide against the side of the strong but
flexible outer
surface of the foot and create very substantial pressure on that outer surface
at the
sides of the foot. But that pressure is precisely resisted and balanced by
tension
along the outer surface of the foot, resulting in a stable equilibrium.
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26
Fig. ~ shows, in cross section of the upright heel deformed by body
weight, the principle of the tension-stabilized sides of the bare foot applied
to the
naturally rounded shoe sole design. The same principle can be applied to
conventional shoes, but is not shown. The key change from the existing art of
shoes is that the sides of the shoe upper 21 (shown as darkened lines) must
wrap
around the outside edges 32 of the rounded shoe sole 28, instead of attaching
underneath the foot to the upper surface 30 of the shoe sole, as is done
conventionally. The shoe upper sides can overlap and be attached to either the
inner (shown on the left) or outer surface (shown on the right) of the bottom
sole,
since those sides are not unusually load-bearing, as shown. Alternatively, the
bottom sole, optimally thin and tapering as shown. can extend upward around
the
outside edges 32 of the shoe sole to overlap and attach to the shoe upper
sides
(shown Fig. ~B). Their optimal position coincides with the Theoretically Ideal
Stability Plane, so that the tension force on the shoe sides is transmitted
directly
all the way down to the bottom surface of the shoe, which anchors it on the
ground with virtually no intervening artificial lever arm. For shoes with only
one
sole layer, the attachment of the shoe upper sides should be at or near the
lower or
bottom surface of the shoe sole.
The design shown in Fig. ~ is based on a fundamentally different
2 o conception: that the shoe upper is integrated into the shoe sole, instead
of attached
on top of it, and the shoe sole is treated as a natural extension of the foot
sole, not
attached to it separately.
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77
The fabric (or other flexible material, like leather) of the shoe uppers
would preferably be non-stretch or relatively so, so as not to be deformed
e:ccessively by the tension placed upon its sides when compressed as the foot
and
shoe tilt. The fabric can be reinforced in areas of particularly high tension,
like
the essential structural support and propulsion elements defined in the
applicant's
earlier applications (the base and lateral tuberosity of the calcaneus, the
base of
the fifth metatarsal, the heads of the metatarsals, and the first distal
phalange).
The reinforcement can take many forms, such as like that of comers of the jib
sail
of a racing sailboat or more simple straps. As closely as possible, it should
have
the same performance characteristics as the heavily callused skin of the sole
of an
habitually bare foot. Preferably, the relative density of the shoe sole is as
described in Figure 46 of the present application with the softest sole
density
nearest the foot sole, a progression through less soft sole density through
the sole,
to the firmest and least flexible at the outermost shoe sole layer. This
arrangement allows the conforming sides of the shoe sole to avoid pro~~iding a
rigid destabilizing lever arm.
The change from eacisting art to provide the tension-stabilized sides shown
in Fig. ~ is that the shoe upper is directly integrated functionally with the
shoe
sole, instead of simply being attached on top of it. The advantage of the
tension-
2o stabilized sides design is that it provides natural stability as close to
that of the
bare foot as possible, and does so economically, with the minimum shoe sole
side
width possible.
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78
The result is a shoe sole that is naturally stabilized in the same way that
the barefoot is stabilized, as seen in Fig. 6, which shows a close-up cross-
section
of a naturally rounded shoe sole 28 (undeformed by body weight) when tilted to
the edge. The same destabilizing force against the side of the shoe shown in
Fig.
2 is now stably resisted by offsetting tension in the surface of the shoe
upper 21
extended down the side of the shoe sole so that it is anchored by the weight
of the
body when the shoe and foot are tilted.
In order to avoid creating unnatural torque on the shoe sole, the shoe
uppers may be joined or bonded only to the bottom sole, not the midsole, so
that
1 o pressure shown on the side of the shoe upper produces side tension only
and not
the destabilizing torque from pulling similar to that described in Fig. 2.
However,
to avoid unnatural torque, the upper areas 147 of the shoe midsole, which form
a
sharp corner, should be composed of relatively soft midsole material. In this
case,
bonding the shoe uppers to the midsole would not create very much
destabilizing
15 torque. The bottom sole 149 is preferably thin, at least on the stability
sides, so
that its attachment overlap with the shoe upper sides coincides, as closely as
possible, to the Theoretically Ideal Stability Plane, so that force is
transmitted by
the outer shoe sole surface to the b ound.
In summary, the Fig. ~ design is for a shoe construction, including: a shoe
2 o upper that is composed of material that is flexible and relatively
inelastic at least
where the shoe upper contacts the areas of the structural bone elements of the
human foot, and a shoe sole that has relatively flexible sides; and at least a
portion of the sides of the shoe upper are attached directly to the bottom
sole,
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29
while enveloping on the outside the other sole portions of the shoe sole. This
construction can either be applied to conventional shoe sole structures or to
the
applicant's prior shoe sole inventions, such as the naturally rounded shoe
sole
conforming to the Theoretically Ideal Stabiliy Plane.
Fig. 7 shows, in cross-section at the heel, the tension-stabilized sides
concept applied to naturally rounded shoe sole 28 when the shoe and foot are
tilted out fully and are naturally deformed by body weight (although constant
shoe
sole thickness is shown undeformed). The figure shows that the shape and
stability function of the shoe sole and shoe uppers mirror almost exactly that
of
the human foot.
Figs. 8A-8D show the natural cushioning of the human bare foot 27, in
cross sections at the heel. Fig. 8A shows the bare heel upright and unloaded,
with
little pressure on the subcalcaneal fat pad 1~8, which is evenly distributed
beriveen the calcaneus 1 ~9, which is the heel bone, and the bottom sole 160
of the
foot.
Fig. 8B shows the bare heel upright but under the moderate pressure of
full body weight. The compression of the calcaneus against the subcalcaneal
fat
pad produces evenly balanced pressure within the subcalcaneal fat pad because
it
is contained and surrounded by a relatively unstretchable fibrous capsule, the
2 o bottom sole of the foot. Underneath the foot, where the bottom sole is in
direct
contact with the ground, the pressure caused by the calcaneus on the
compressed
subcalcaneal fat pad is transmitted directly to the ground. Simultaneously,
substantial tension is created on the sides of the bottom sole of the foot
because of
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JO
the surrounding relatively touch fibrous capsule. That combination of bottom
pressure and side tension is the foot's natural shock absorption system for
support
structures like the calcaneus and the other bones of the. foot that come in
contact
with the ground.
Of equal functional importance is that lower surface 167 of those support
structures of the foot like the calcaneus and other bones make firm contact
with
the upper surface 168 of the foot's bottom sole underneath, with relatively
little
uncompressed fat pad intervening. In effect, the support structures of the
foot
land on the ground and are firmly supported; they are not suspended on top of
springy material in a buoyant manner analogous to a water bed or pneumatic
tire,
as in some existing proprietary shoe sole cushioning systems. This
simultaneously firm and yet cushioned support provided by the foot sole must
have a significantly beneficial impact on energy efficiency, also called
energy-
return, different from some conventional shoe sole designs which provide shock
absorption cushioning during the landing and support phases of locomotion at
the
expense of firm support during the take-off phase.
The incredible and unique feature of the foot's natural system is that. once
the calcaneus is in fairly direct contact with the bottom sole and therefore
providinD firm support and stability, increased pressure produces a more rigid
2 o fibrous capsule that protects the calcaneus and produces greater tension
at the
sides to absorb shock. So, in a sense, even when the foot's suspension system
would seem in a conventional way to have bottomed out under normal body
weight pressure, it continues to react with a mechanism to protect and cushion
the
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31
foot even under very much more extreme pressure. This is seen in Fig. 8C,
which
shows the human heel under the heat' pressure of roughly three times body
weight force of landing during routine running. This can be easily verified:
when
one stands barefoot on a hard floor, the heel feels very firmly supported and
yet
can be lifted and virtually slammed onto the floor with little increase in the
feeling of firmness; the heel simply becomes harder as the pressure increases.
In additiori, it should be noted that this system allows the relatively
narrow base of the calcaneus to pivot from side to side freely in normal
pronation/supination motion, without any obstructing torsion on it, despite
the
i o very much greater width of compressed foot sole providing protection and
cushioning. This is crucially important in maintaining natural alignment of
joints
above the ankle joint such as the knee, hip and back, particularly in the
horizontal
plane, so that the entire body is properly adjusted to absorb shock correctly.
In
contrast, existing shoe sole designs, which are generally relatively wide to
provide
15 stability, produce unnatural frontal plane torsion on the calcaneus,
restricting its
natural motion, and causing misalignment of the joints operating above it,
resulting in the overuse injuries unusually common with such shoes. Instead of
flexible sides that harden under tension caused by pressure like that of the
foot,
some existing shoe sole designs are forced by lack of other alternatives to
use
2 o relatively rigid sides in an attempt to provide su~cient stability to
offset the
otherwise uncontrollable buoyancy and lack of firm support of air or gel
cushions.
Fig. 8D shows the bare foot deformed under full body weight and tilted
laterally to roughly the 20 degree limit of normal movement range. Again it is
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clear that the natural system provides both firm lateral support and stability
by
providing relatively direct contact with the ground. while at the same time
providing a cushioning mechanism through side tension and subcalcaneal fat pad
pressure.
Figs. 9A-9D show, also in cross-sections at the heel, a naturally rounded
shoe sole design that parallels as closely as possible the overall natural
cushioning
and stability system of the barefoot described in Fig. 8, including a
cushioning
compartment 161 under support structures of the foot containing a pressure-
transmitting medium like gas, gel, or liquid, like the subcalcaneal fat pad
under
the calcaneus and other bones of the foot. Consequently, Figs. 9A-D directly
correspond to Figs. 8A-D. The optimal pressure-transmitting medium is that
which most closely approximates the fat pads of the foot. Silicone gel is
probably
most optimal of materials currently readily available, but future improvements
are
probable. Since it transmits pressure indirectly, in that it compresses in
volume
1 s under pressure, gas is significantly less optimal. The gas, gel, or
liquid, or any
other effective material, can be further encapsulated itself, in addition to
the sides
of the shoe sole, to control leakage and maintain uniformity, as is common
conventionally, and can be subdivided into any practical number of
encapsulated
areas within a compartment, again as is common conventionally. The relative
2 o thickness of the cushioning compartment 161 can vary, as can the bottom
sole
149 and the upper midsole 147, and can be consistent or differ in various
areas of
the shoe sole. The optimal relative sizes should be those that approximate
most
closely those of the average human foot, which suggests both smaller upper and
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JJ
lower soles and a larger cushioning compartment than shown in Fig. 9. The
cushioning compartments or pads 161 can be placed anywhere from directly
underneath the foot, like an insole, to directly above the bottom sole.
Optimally,
the amount of compression created by a given load in any cushioning
compartment 161 should be tuned to approximate as closely as possible the
compression under the corresponding fat pad of the foot.
The function of the subcalcaneal fat pad is not met satisfactorily with
existing proprietary cushioning systems, even those featuring gas, gel or
liquid as
a pressure transmitting medium. In contrast to those artificial systems, the
design
shown in Fig. 9 conforms to the natural contour of the foot and to the natural
method of transmitting bottom pressure into side tension in the flexible but
relatively non-stretching (the actual optimal elasticity will require
empirical
studies) sides of the shoe sole.
Some existing cushioning systems do not bottom out under moderate
i ~ loads and rarely if ever do so under extreme loads. Rather, the upper
surface of
the cushioning device remains suspended above the lower surface. In contrast,
the design in Fig. 9 provides firm support to foot support structures by
providing
for actual contact between the lower surface 16~ of the upper midsole 147 and
the
upper surface 166 of the bottom sole 149 when fully loaded under moderate body
2 o weight pressure, as indicated in Fig. 9B, or under maximum normal peak
landing
force during running, as indicated in Fig. 9C, just as the human foot does in
Figs.
8B and 8C. The greater the downward force transmitted through the foot to the
shoe, the greater the compression pressure in the cushioning compartment 161
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34
and the greater the resulting tension on the shoe sole sides.
Fig. 9D shows the same shoe sole design when fully loaded and tilted to
the natural 20 degree lateral limit, like Fia. 8D. Fig. 9D shows that an added
stability benefit of the natural cushioning system for shoe soles is that the
effective thickness of the shoe sole is reduced by compression on the side so
that
the potential destabilizing lever arm represented by the shoe sole thickness
is also
reduced, and thus foot and ankle stability is increased. Another benefit of
the Fia.
9 design is that the upper midsole shoe surface can move in any horizontal
direction, either sideways or front to back in order to absorb shearing
forces. The
a shearing motion is controlled by tension in the sides. Note that the right
side of
Figs. 9A-D is modified to provide a natural crease or upward taper 162, which
allows complete side compression without binding or bunching bet~-een the
upper and lower shoe sole layers 147, 148. and 149. The shoe sole crease 162
parallels exactly a similar crease or taper 163 in the human foot. Further,
201
represents a horizontal line through the lower most point of the upper surface
30
of the shoe sole.
Another possible variation of joining shoe upper to shoe bottom sole is on
the right (lateral) side of Figs. 9A-D, which makes use of the fact that it is
optimal
for the tension absorbing shoe sole sides, whether shoe upper or bottom sole,
to
2 o coincide with the Theoretically Ideal Stability Plane along the side of
the shoe
sole beyond that point reached when the shoe is tilted to the foot's natural
limit, so
that no destabilizing shoe sole lever arm is created when the shoe is tilted
fully, as
in Fig. 9D. The joint may be moved up slightly so that the fabric side does
not
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~J
come in contact with the ground, or it may be covered with a coating to
provide
both traction and fabric protection.
It should be noted that the Fig. 9 design provides a structural basis for the
shoe sole to conform very easily to the natural shape of the human foot and to
parallel easily the natural deformation flattening of the foot during load-
bearing
motion on the ground. This is true even if the shoe sole is made
conventionally
with a flat sole, as long as rigid structures such as heel counters and motion
control devices are not used; though not optimal, such a conventional flat
shoe
made like Fig. 9 would provide the essential features of the invention
resulting in
o significantly improved cushioning and stability. The Fig. 9 design could
also be
applied to intermediate-shaped shoe soles that neither conform to the flat
ground
or the naturally rounded foot. 1n addition, the Fig. 9 design can be applied
to the
applicant's other designs, such as those described in Figs. 14-28 of the
present
application.
In summary, the Fig. 9 design shows a shoe construction for a shoe,
including: a shoe sole with a compartment or compartments under the structural
elements of the human foot, including at least the heel; the compartment or
compartments contain a pressure-transmitting medium like liquid, gas, or gel;
a
portion of the upper surface of the shoe sole compartment firmly contacts the
20 lower surface of said compartment during normal load-bearing; and pressure
from
the load-bearing is transmitted progressively at least in part to the
relatively
inelastic sides, top and bottom of the shoe sole compartment or compartments,
producing tension.
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36
While the Fig. 9 design copies in a simplified way the macro structure of
the foot, Figs. 10 A-C focus more on the exact detail of shoe soles modeled
after
the natural structures of the foot, including at the micro level. Figs. l0A
and l OC
are perspective views of cross sections of a part of a rounded shoe sole 28
with a
structure like the human heel , wherein elements of the shoe sole structure
are
similar to chambers of a matrix of elastic fibrous connective tissue which
hold
closely packed fat cells in the foot 164. The chambers in the foot are
structured as
whorls radiating out from the calcaneus. These fibrous-tissue strands are
firmly
attached to the undersurface of the calcaneus and extend to the subcutaneous
1 o tissues. They are usually in the form of the letter U, with the open end
of the U
pointing toward the calcaneus.
As the most natural, an approximation of this specific chamber structure
would appear to be the most optimal as an accurate model for the structure of
the
shoe sole cushioning compartments 161. The description of the structure of
1~ calcaneal padding provided by Erich Blechschmidt in Foot and Ankle, March,
198?, (translated from the original 1933 article in German) is so detailed and
comprehensive that copying the same structure as a model in shoe sole design
is
not difficult technically, once the crucial connection is made that such
copying of
this natural system is necessary to overcome inherent weaknesses in the design
of
2 o existing shoes. Other arrangements and orientations of the whorls are
possible,
but would probably be less optimal.
Pursuing this nearly exact design analogy, the lower surface 16~ of the
upper midsole 147 would correspond to the outer surface 167 of the calcaneus
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J7
1 ~9 and would be the origin of the U shaped whorl chambers 16=1 noted above.
Fig. l OB shows a close-up of the interior structure of the large chambers
of a rounded shoe sole 28 as shown in Figs. l0A and l OC, with mini-chambers
180 similar to mini-chambers in the foot. It is clear from the fine interior
structure and compression characteristics of the mini-chambers 180 in the foot
that those directly under the calcaneus become very hard quite easily, due to
the
high local pressure on them and the limited degree of their elasticity, so
they are
able to provide very firm support to the calcaneus or other bones of the foot
sole.
By virtue of their being fairly inelastic, the compression forces on those
compartments are dissipated to other areas of the nerivork of fat pads under
any
given support structure of the foot, like the calcaneus. Consequently, if a
cushioning compartment 161, such as the compartment under the heel shown in
Fig. 9, is subdivided into smaller chambers, like those shown in Fig. 10, then
actual contact between the lower surface of the upper midsole 16~ and the
upper
i 5 surface of the bottom sole 166 would no longer be required to provide firm
support, so long as those compartments and the pressure-transmitting medium
contained in them have material characteristics similar to those of the foot,
as
described above. The use of gas may not be satisfactory in this approach,
since its
compressibility may not allow adequate firmness.
2o In summary, the Fig. 10 design shows a shoe construction including: a
shoe sole with a compartments under the structural elements of the human foot,
including at least the heel; the compartments containing a pressure-
transmitting
medium like liquid, gas, or gel; the compartments having a whorled structure
like
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3S
that of the fat pads of the human foot sole; load-bearing pressure being
transmitted progressively at least in part to the relatively inelastic sides,
top and
bottom of the shoe sole compartments, producing tension therein; the
elasticity of
the material of the compartments and the pressure-transmitting medium are such
that normal weight-bearing loads produce sufficient tension within the
structure
of the compartments to provide adequate structural rigidity to allow firm
natural
support to the foot structural elements, like that provided by the fat pads of
the
bare foot. That shoe sole construction can have shoe sole compartments that
are
subdivided into mini-chambers like those of the fat pads of the foot sole.
1 o Since the bare foot that is never shod is protected by very hard calluses
(called a "seri boot") which the shod foot lacks, it seems reasonable to infer
that
natural protection and shock absorption system of the shod foot is adversely
affected by its unnaturally undeveloped fibrous capsules (surrounding the
subcalcaneal and other fat pads under foot bone support structures). A
solution
~5 would be to produce a shoe intended for use without socks (i.e. with smooth
surfaces above the foot bottom sole) that uses insoles that coincide with the
foot
bottom sole, including its sides. The upper surface of those insoles, which
would
be in contact with the bottom sole of the foot (and its sides), would be
coarse
enough to stimulate the production of natural barefoot calluses. The insoles
2 o would be removable and available in different uniform grades of
coarseness, as is
sandpaper, so that the user can progress from finer grades to coarser grades
as his
foot soles toughen with use.
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39
Similarly, socks could be produced to serve the same function. ~.vith the
area of the sock that corresponds to the foot bottom sole (and sides of the
bottom
sole) made of a material coarse enough to stimulate the production of calluses
on
the bottom sole of the foot, with different grades of coarseness available,
from
fine to coarse, corresponding to feet from soft to naturally tough. Using a
tube
sock design with uniform coarseness, rather than conventional sock design
assumed above, would allow the user to rotate the sock on his foot to
eliminate
any "hot spot" irntation points that might develop. Also, since the toes are
most
prone to blistering and the heel is most important in shock absorption, the
toe area
of the sock could be relatively less abrasive than the heel area.
The invention shown in Figures 11 A-11 C is a removable and re-
insertable, non-orthotic midsole section 14~. Alternatively, the non-orthotic
midsole section 14~ can be attached permanently to adjoining portions of the
rounded shoe sole 28 after initial insertion using glue or other common forms
of
i5 attachment. The rounded shoe sole 28 has an upper surface 30 and a lower
surface 31 with at least a part of both surfaces being concavely rounded, as
viewed in a frontal plane from inside the shoe when in an unloaded and upright
condition. Preferably, all or a part of the midsole section 14~ can be
removable
through any practical number of insertion/removal cycles. The removable
2o midsole 14~ can also, optionally, include a concavely rounded side, as
shown in
Fig. 1 lA, or a concavely rounded underneath portion or be conventionally
formed, with other portions of the shoe sole including concave rounding on the
side or underneath portion or portions. All or part of the preferred insole 2
can
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also be removable or can be integrated into the upper portion of the midsole
section 14~.
The removable portion or portions of the midsole section 14~ can
include all or part of the heel lift (not shown) of the rounded shoe sole 28,
or all
or part of the heel lift 38 can be incorporated into the bottom sole 149
permanently, either using bottom sole material, midsole material, or other
suitable material. Heel lift 38 is typically formed from cushioning material
such as the midsole materials described herein and may be integrated with the
upper midsole 147 or midsole 148 or any portion thereof, including the
1 o removable midsole section 145.
The removable portion of the midsole section 14~ can extend the entire
length of the shoe sole, as shown in Figs. 11 K and 11 L, or only a part of
the
length, such as a heel area as shown in cross-section in Fig. 11 G, a
midtarsal
area as shown in cross-section in Fig. 11 H, a forefoot area as shown in cross-
15 section in Figs. 1 lI and 11J, or some portion or combination of those
areas.
The removable portion and/or midsole section 14~ may be fabricated in any
suitable, conventional manner employed for the fabrication of shoe midsoles or
other, similar structures.
The midsole section 14~ , as well as other midsole portions of the shoe
2 o sole such as the midsole 148 and the upper midsole 147, can be fabricated
from
any suitable material such as elastomeric foam materials. Examples of current
art for elastomeric foam materials include polyether urethane, polyester
urethane, polyurethane foams, ethylene vinyl acetate, ethylene vinyl
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41
acetate/polyethylene copolymer, polyester elastomers such as Hytrel ~.,
tluoroelastomers, chlorinated polyethylene, chlorosulfonated polyethylene,
acrylonitrile rubber, ethylene vinyl acetate/polypropylene copolymers,
polyethylene, polypropylene, neoprene, natural rubber, Dacron0 polyester,
polyvinyl chloride, thermoplastic rubbers, nitrile rubber, butyl rubber,
sulfide
rubber, polyvinyl acetate, methyl rubber, bung N, buna S, polystyrene,
ethylene
propylene polymers, polybutadiene, butadiene styrene rubber, and silicone
rubbers. The most preferred elastomeric foam materials in the current art of
shoe sole midsole materials are polyurethanes, ethylene vinyl acetate,
ethylene
vinyl acetate/polyethylene copolymers, ethylene vinyl acetate/polypropylene
copolymers, neoprene and polyester elastomers. Suitable materials are selected
on the basis of durability, flexibility and resiliency for cushioning the
foot,
among other properties.
As shown in Figure 11 D, the midsole section 145 itself can incorporate
cushioning or structural compartments or components. Figure 11D shows
cushioning compartments or chambers 161 encapsulated in part of midsole
section 145, as well as bottom sole 149, as viewed in a frontal plane cross-
section. Figure 11D is a perspective view to indicate the placement of disks
or
capsules of cushioning material. The disks or capsules of cushioning material
2 o may be made from any of the midsole materials mentioned above, and
preferably include a flexible, resilient midsole material such as ethyl vinyl
acetate (EVA), that may be softer or firmer than other sole material or may be
provided with special shock absorption, energy efficiency, wear, or stability
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42
characteristics. The disks or capsules may include a gas, gel, liquid or any
other
suitable cushioning material. The cushioning material may optionally be
encapsulated itself using a film made of a suitable material such as
polyurethane film. Other similar materials may also be employed. The
encapsulation can be used to form the cushioning material into an inse=table
capsule in a conventional manner. The example shown in Figure 11 D shows
such cushioning disks 161 located in the heel area and the lateral and medial
forefoot areas, proximate to the heads of the first and fifth metatarsal bones
of a
wearer's foot. The cushioning material, for example disks or compartments
161, may form part of the upper surface of the upper portion of the midsole
sectionl4~ as shown in Fig. 11D. A cushioning compartment or disk 161 can
generally be placed anywhere in the removable midsole section 14~ or in only a
part of the midsole section 14~. A part of the cushioning compartment or disk
161 can extend into the outer sole 149 or other sole portion, or,
alternatively,
one or more compartments or disks 161 may constitute all or substantially all
of
the midsole section 14~. As shown in Figure 11L, cushioning disks or
compartments may also be suitably located at other essential support elements
like the base of the fifth metatarsal 97, the head of the first distal
phalange 98,
or the base and lateral tuberosity of the calcaneus 9~, among other suitable
2 o conventional locations. In addition, structural components like a shank
169 can
also be incorporated partially or completely in a midsole section 14~, such as
in
the medial midtarsal area, as shown in Figure 11D, under the main longitudinal
arch of a wearer's foot, and/or under the base of the wearer's fifth
metatarsal
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43
bone, or other suitable alternative locations.
In one embodiment, the Figure 11 D invention can be made of all mass-
produced standard size components, rather than custom fit, but can be
individually tailored for the right and left shoe with variations in the
firmness of
the material in compartments 161 for special applications such as sports
shoes,
golf shoes or other shoes which may require differences between firmness of
the left and right shoe sole.
One of the advantages provided by the removable midsole section 14~
of the present invention is that it allows replacement of foamed plastic
portions
of the midsole which degrade quickly with wear. losing their designed level of
resilience, with new midsole material as necessary over the life of the shoe
to
thereby maintain substantially optimal shock absorption and energy return
characteristics of the rounded shoe sole 28.
The removable midsole section 14~ can also be transferred from one
pair of shoes composed generally of shoe uppers and bottom sole like Figure
11 C to another pair like Figure 11 C, providing cost savings.
Besides using the removable midsole section 14~ to replace worn
components with new components, the replacement midsole section 145 can
provide another advantage of allowing the use of different cushioning or
2 o support characteristics in a single shoe or pair of shoes made like Figure
11 C,
such as firmer or softer portions of the midsole, or thicker or thinner
portions of
the midsole, or entire midsoles that are firmer, softer. thicker or thinner,
either
as separate layers or as an integral part of midsole section 14~. In this
manner,
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=1=1
a single pair of shoes can be customized to provide the desired cushioning or
support characteristics for a particular activity or different levels of
activity,
such as running, training or racing shoes. Figure 11D shows an example of
such removable portions of the midsole in the form of disks or capsules 161,
but midsole or insole layers or the entire midsole section 14~ can be removed
and replaced temporarily or permanently.
Such replacement midsole sections 14~ can be made to include density
or firmness variations like those shown in Figures 21-23 and 2~. The midsole
density or firmness variations can differ between a right foot shoe and a left
1 o foot shoe, such as Figure 21 as a left shoe and Figure 22 as a right shoe,
showing equivalent portions.
Such replacement removable midsole sections 14~ can be made to
include thickness variations, including those shown in Figures 17-20, 2=~, 27,
or
28. Combinations of density or firmness variations and thickness variations
l~ shown above can also be made in the replacement midsole sections 14~.
Replacement removable midsole sections 14~ may be held in position at
least in part by enveloping sides of the shoe upper 21 and/or bottom sole 149.
Alternatively, a portion of the midsole material may be fixed in the shoe sole
and extend up the sides to provide support for holding removable midsole
2 o sections 14~ in place. If the associated rounded shoe sole 28 has one or
more of
the abbreviated sides shown in Figure 11L, then the removable midsole section
can also be held in position against relative motion in the sagittal plane by
indentations formed between one or more concavely rounded sides and the
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4~
adjacent abbreviations. Combinations of these various embodiments may also
be employed.
The removable midsole section 14~ has a lower surface interface 8 with
the upper surface of the bottom sole 149. The interface 8 would typically
remain unglued, to facilitate repeated removal of the midsole sections 14~, or
could be affixed by a weak glue, like that of self stick removable paper
notes,
that does not permanently fix the position of the midsole section 14~ in
place.
The interface 8 can also be bounded by non-slip or controlled slippage
surfaces. The two surfaces which form the interface 8 can have interlocking
complementary geometry's as shown, for example, in Figs. 11 E-11 F. such as
mating protrusions and indentations, or the removable midsole section 14~ may
be held in place by other conventional temporary attachments, such as, for
example, Velcro~ strips. Conversely, providing no means to restrain slippage
between the surfaces of interface 8 may, in some cases, provide additional
~s injury protection. Thus, controlled facilitation of slippage at the
interface 8,
may be desirable in some instances and can be utilized within the scope of the
invention.
The removable midsole section 14~ of the present invention may be
inserted and removed in the same manner as conventional removable insoles or
2 o conventional midsoles, that is, generally in the same manner as the wearer
inserts his foot into the shoe. Insertion of the removable midsole section 14~
may, in some cases, requiring loosening of the shoe laces or other mechanisms
for securing the shoe to a wearer's foot. For example, the midsole section 14~
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46
may be inserted into the interior caviri~ of the shoe upper and affixed to or
abutted against, the top side of the shoe sole. In a particularly preferred
embodiment, a bottom sole 149 is first inserted into the interior cavity of
the
shoe upper 21 as indicated by the arrow in Fia. 7~A. The bottom sole 149 is
inserted into the cavity so that any rounded stability sides 28a are inserted
into
and protrude out of corresponding openings in the shoe upper 21. The bottom
sole 149 is then attached to the upper 21, preferably by a stitch that weaves
around the outer perimeter of the openings thereby connecting the shoe upper
21 to the bottom sole 149. In addition, an adhesive can be applied to the
io surface of the upper 21 which will contact the bottom sole 149 before the
bottom sole 149 is inserted into the upper 21.
Once the bottom sole 149 is attached, the removable midsole section
14~ may then be inserted into the interior cavity of the upper 21 and affixed
to
the top side of the bottom sole 149, as shown in Fig. 7~C. The midsole section
14~ can be releasably secured in place by any suitable method, including
mechanical fasteners, adhesives, snap-fit arrangements, reclosable
compartments, interlocking geometry's and other similar structures.
Additionally, the removable midsole section 14~ preferably includes
protrusions placed in an abutting relationship with the bottom sole 149 so
that
2 o the protrusions occupy corresponding recesses in the bottom sole 149.
Alternatively, the removable midsole section 14~ may be glued to affix
the midsole section 14~ in place on the bottom sole 149. In such an
embodiment, an adhesive can be used on the bottom side of the midsole section
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47
14~ to secure the midsole to the bottom sole 149.
Replacement removable midsole sections 14~ with concavely rounded
sides that provide support for only a narrow range of sideways motion or with
higher concavely rounded sides that provide for a very wide range of sideways
motion can be used to adapt the same shoe for different sports, like running
or
basketball. for which lessor or greater protection against ankle sprains may
be
considered necessary, as shown in Figure 11 G. Different removable midsole
sections 14~ may also be employed on the left or right side, respectively.
Replacement removable midsole sections 14> with higher curved sides that
provide for an extra range of motion for sports which tend to encourage
pronation-prone wearers on the medial side, or on the lateral side for sports
which tend to encourage supination-prone wearers are other potentially
beneficial embodiments.
Individual removable midsole sections 14~ can be custom made for a
specific class of wearer or can be selected by the individual from mass-
produced standard sizes with standard variations in the height of the
concavely
rounded sides, for example.
Figs. 11 M-11 P show shoe soles with one or more encapsulated midsole
sections or chambers such as bladders 188 for containing fluid such as a gas,
2 0 liquid, gel or other suitable materials, and with a duct, a flow
regulator, a
sensor, and a control system such as a microcomputer. The existing art is
described by U.S. Patent No. x,813,142 by Demon, issued September 29, 1998
and by the references cited therein.
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48
Figs. 11NI-11P also include the inventor's concavely rounded sides as
described elsewhere in this application, such as figs. 11 A-11 L (and/or
concavely rounded underneath portions). In addition, Figs. 11 M-11 P show
ducts that communicate between encapsulated midsole sections or
chambers/bladders 188 or within portions of the encapsulated midsole sections
or bladders 188. Other suitable conventional embodiments can also be used in
combination with the applicant's concavely rounded portions. Also, Figs. 11N-
11 P show removable midsole sections 14~. Fig. 1 I M shows a non-removable
midsole in combination with the pressure controlled bladder or encapsulated
section 188 of the invention. The bladders or sections 188 can be any size
relative to the midsole encapsulating them, including replacing the
encapsulating midsole substantially or entirely.
Also, included in the applicant's invention, but not shown, is the use of
a piezo-electric effect controlled by a microprocessor control system to
affect
~5 the hardness or firmness of the material contained in the encapsulated
midsole
section, bladder, or other midsole portion 188. For example, a disk-shaped
midsole or other suitable material section 161, may be controlled by electric
current flow instead of fluid flow, with common electrical components
replacing those described below which are used for conducting and controlling
2 o fluid flow under pressure.
Figure 11 M shows a shoe sole embodiment with the applicant's
concavely rounded sides invention described in earlier figures, including both
concavely rounded sole inner and outer surfaces, with a bladder or an
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=19
encapsulated midsole section 188 in both the medial and lateral sides and in
the
middle or underneath portion between the sides. An embodiment with a
bladder or encapsulated midsole section 188 located in only a single side and
the middle portion is also possible, but not shown, as is a an embodiment with
a
.. bladder or encapsulated midsole section 188 located in both the medial and
lateral sides without one in the middle portion. Each of the bladders 188 is
connected to an adjacent bladders) 188 by a fluid duct 206 passing through a
fluid valve 210, located in midsole section 14~, although the location could
be
anywhere in a single or mufti-layer rounded shoe sole 28. Figure 11M is based
on the left side of Figure 13A. In a piezo-electric embodiment using midsole
sections 188, the fluid duct bet'veen sections would be replaced by a suitable
W red or wireless connection, not shown. A combination of one or more
bladders 188 with one or more midsole sections is also possible but not shown.
One advantage of the applicant's invention, as shown in the applicant's
1 s Fig. 11 M, is to provide better lateral or side-to-side stability through
the use of
rounded sides, to compensate for excessive pronation or supination, or both,
when standing or during locomotion. The Figure 11 M embodiment also shows
a fluid containment system that is fully enclosed and which uses other
bladders
188 as reservoirs to provide a unique advantage. The advantage of the Figure
20 11M embodiment is to provide a structural means by which to change the
hardness or firmness of each of the shoe sole sides and of the middle or
underneath sole portion, relative to the hardness or firmness of one or both
of
the other sides or sole portion, as seen for example in a frontal plane, as
shown,
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or in a sagittal plane (not shown).
Although Figure 11M shows communication between each bladder or
midsole section 188 within a frontal plane (or sagittal plane), which is a
highly
effective embodiment, communication might also be betty ~een only rivo
adjacent
.. or non-adjacent bladders or midsole sections 188 due to cost, weight, or
other
design considerations. The operation of the applicant's invention, beyond that
described herein with the exceptions specifically indicated, is as is known in
the
prior art, specifically the Demon ' 142 patent. the relevant portions of
which,
such as the disclosure of suitable system and electronic circuitry shown in
schematic representations in Figures 2, 6, and 7 of the Demon ' 142 patent and
the pressure sensitive variable capacitor shown in Figure ~, as well as the
textual specification associated with those figures, are hereby incorporated
by
reference.
Each fluid bladder or midsole section 188 may be provided with an
associated pressure sensing device that measures the pressure exerted by the
user's foot on the fluid bladder or midsole section 188. As the pressure
increases above a threshold, a control system opens (perhaps only partially) a
flow regulator to allow fluid to escape from the fluid bladder or section 188.
Thus, the release of fluid from the fluid bladder or section 188 may be
2o employed to reduce the impact of the user's foot on the ground. Point-
pressure
under a single bladder 188, for example, can be reduced by a controlled fluid
outflow to any other single bladder or any combination of the other bladders.
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Preferable, the sole of the shoe is divided into zones which roughly
correspond to the essential structural support and propulsion elements of the
intended wearer's foot, including the base of the calcaneus, the lateral
tuberosit<-
of the calcaneus 9~, the heads of the metatarsals 96 (particularly the first
and
fifth), the base of the fifth metatarsal. the main longitudinal arch
(optional), and
the head of the first distal phalange 98. The zones under each individual
element can be merged with adjacent zones, such as a lateral metatarsal head
zone 96e and a medial metatarsal head zone 96d.
The pressure sensing system preferably measures the relative change in
pressure in each of the zones. The fluid pressure system thereby reduces the
impact experienced by the user's foot by regulating the escape of a fluid from
a
fluid bladder or midsole section 188 located in each zone of the sole. The
control system 300 receives pressure data from the pressure sensing system and
controls the fluid pressure system in accordance with predetermined criteria
n 5 which can be implemented via electronic circuitry, software or other
conventional means.
The pressure sensing system may include a pressure sensing device 104
disposed in the sole of the shoe at each zone. In a preferred embodiment, the
pressure sensing device 104 is a pressure sensitive variable capacitor which
2 o may be formed by a pair of parallel flexible conductive plates disposed on
each
side of a compressible dielectric. The dielectric can be made from any
suitable
material such as rubber or another suitable elastomer. The outside of the
flexible conductive plates are preferably covered by a flexible sheath (such
as
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nibber) for added protection.
Since the capacitance of a parallel plate capacitor is inversely
proportional to the distance between the plates, compressing the dielectric by
applying increasing pressure results in an increase in the capacitance of the
pressure sensitive variable capacitor. When the pressure is released, the
dielectric expands substantially to its original thickness so that the
pressure
sensitive variable capacitor returns substantially to its original
capacitance.
Consequently, the dielectric must have a relatively high compression limit and
a
high degree of elasticity to provide ideal function under variable loading.
to The pressure sensing system also includes pressure sensing circuitry 120
which converts the change in pressure detected by the variable capacitor into
digital data. Each variable capacitor forms part of a conventional frequency-
to-
voltage converter (FVC) which outputs a voltage proportional to the
capacitance of variable capacitor. An adjustable reference oscillator may be
s electrically connected to each FVC. The voltage produced by each of the FVCs
is provided as an input to a multiplexer which cycles through the channels
sequentially connecting the voltage from each FVC to an analog to-digital
(A/D) converter to convert the analog voltages into digital data for
transmission
to control system 300 via data lines, each of which is connected to control
2o system 300. The control system 300 can control the multiplexer to
selectively
receive data from each pressure sensing device in any desirable order. These
components and circuitry are well known to those skilled and the art and any
suitable component or circuitry might be used to perform the same function.
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The fluid pressure system selectively reduces the impact of the user's
foot in each of the zones. Associated with each pressure sensing device 104 in
each zone, and embedded in the shoe sole, is at least one bladder or midsole
section 188 which forms part of the fluid pressure system. A fluid duct 206 is
connected at its first end to its respective bladder or section 188 and is
connected at its other end to a fluid reservoir. In this embodiment, fluid
duct
206 connects bladder or midsole section 188 with ambient air, which acts as a
fluid reservoir, or, in a different embodiment, with another bladder 188 also
acting as a fluid reservoir. A flow regulator, which in this embodiment is a
1o fluid valve 210, is disposed in fluid duct 206 to regulate the flow of
fluid
through fluid duct 206. Fluid valve 210 is adjustable over a range of openings
(i.e., variable metering) to control the flow of fluid exiting bladder or
section
188 and may be any suitable conventional valve such as a solenoid valve as in
this embodiment.
is Control system 300, which preferably includes a programmable
microcomputer having conventional RAM and/or ROM, receives information
from the pressure sensing system indicative of the relative pressure sensed by
each pressure sensing device 104. Control system 300 receives digital data
from pressure sensing circuitry 120 proportional to the relative pressure
sensed
2o by pressure sensing devices 104. Control system 300 is also in
communication
with fluid valves 210 to vary the opening of fluid valves 210 and thus control
the flow of fluid. As the fluid valves of this embodiment are solenoids (and
thus electrically controlled), control system 300 is in electrical
communication
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~4
with fluid valves 210. An analog electronic control system 300 with other
components being analog is also possible.
The preferred programmable microcomputer of control system 300
selects (via a control line) one of the digital-to-analog (D/A) converters to
receive data from the microcomputer in order to control fluid valves 210. The
selected D/A converter receives the data and produces an analog voltage
proportional to the digital data received. The output of each D/A converter
remains constant until changed by the microcomputer (which can be
accomplished using conventional data latches, which is not shown). The output
of each D/A converter is supplied to each of the respective fluid valves 210
to
selectively control the size of the opening of fluid valves 210.
Control system 300 also can include a cushioning adjustment control to
allow the user to control the level of cushioning response from the shoe. A
control device on the shoe can be adjusted by the user to provide adjustments
in
1 s cushioning ranging from no additional cushioning (fluid valves 210 never
open)
to maximum cushioning (fluid valves 210 open wide). This is accomplished by
scaling the data to be transmitted to the D/A converters (which controls the
opening of fluid valves 210) by the amount of desired cushioning as received
by
control system 300 from the cushioning adjustment control. However, any
2o suitable conventional means of adjusting the cushioning could be used.
An illuminator, such as a conventional light emitting diode (LED), can
be mounted to the circuit board that houses the electronics of control system
300 to provide the user with an indication of the state of operation of the
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JJ
apparatus.
The operation of this embodiment of the present invention is most
useful for applications in which the user is either walking or running for an
extended period of time during which weight is distributed among the zones of
the foot in a cyclical pattern. The system begins by performing an
initialization
process which is used to set up pressure thresholds for each zone. During
initialization, fluid valves 210 are fully closed while the bladders or
sections
188 are in their uncompressed state (e.g., before the user puts on the shoes).
In
this configuration, no fluid, including a gas like air, can escape the
bladders or
sections 188 regardless of the amount of pressure applied to the bladders or
sections 188 by the user's foot. As the user begins to walk or run with the
shoes
on, control system 300 receives and stores measurements of the change in
pressure of each zone from the pressure sensing system. During this period,
fluid valves 210 are kept closed.
Next, control system 300 computes a threshold pressure for each zone
based on the measured pressures for a given number of strides. In this
embodiment, the system counts a predetermined number of strides, i.e. ten
strides (by counting the number of pressure changes), but another system might
simply store data for a given period of time (e.g. twenty seconds). The number
2 0 of strides are preprogrammed into the microcomputer but might be inputted
by
the user in other embodiments. Control system 300 then examines the stored
pressure data and calculates a threshold pressure for each zone. The
calculated
threshold pressure, in this embodiment, will be less than the average peak
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~6
pressure measured and is in part determined by the ability of the associated
bladder or section 188 to reduce the force of the impact as explained in more
detail below.
After initialization, control system 300 will continue to monitor data
from the pressure sensing system and compare the pressure data from each zone
with the pressure threshold of that zone. When control system 300 detects a
measured>pr~"~SSUr_E, that is greater than the pressure threshold for that
zone,
control system 300 opens the fluid valve 210 (in a manner as discussed above)
associated wzth that pressure zone to allow fluid to escape from the bladder
or
section 188 into the fluid reservoir at a controlled rate. In this embodiment,
air
escapes from bladder or section 188 through fluid duct 206 (and fluid valve
210
disposed therein) into ambient air. The release of fluid from the bladder or
section 188 allows the bladder or section 188 to deform and thereby lessens
the
"push back" of the bladder. The user experiences a "softening" or enhanced
15 cushioning of the sole of the shoe in that zone, which reduces the impact
on the
user's foot in that zone.
The size of the opening of fluid valve 210 should allow fluid to escape
the bladder or section 188 in a controlled manner. The fluid should not escape
from bladder or section 188 so quickly that the bladder or section 188 becomes
2 o fully deflated (and can therefore supply no additional cushioning) before
the
peak of the pressure exerted by the user. However, the fluid must be allowed
to
escape from the bladder or section 188 at a high enough rate to provide the
desired cushioning. Factors which will bear on the size of the opening of the
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J~
flow regulator include the viscosity of the fluid, the size of the fluid
bladder, the
pressure exerted by fluid in the fluid reservoir, the peak pressure exerted
and
the length of time such pressure is maintained.
As the user's foot leaves the traveling surface, a fluid like air is forced
back into the bladder or section 188 by a reduction in the internal air
pressure of
the bladder or section 188 (i.e., a vacuum is created) as the bladder or
section
188 returns to its non-compressed size and shape. After control system 300
receives pressure data from the pressure sensing system indicating that no
pressure (or minimal pressure) is being applied to the zones over a
io predetermined length of time (long enough to indicate that the shoe is not
in
contact with the traveling surface and that the bladders or sections 188 have
returned to their non-compressed size and shape), control system 300 again
closes all fluid valves 210 in preparation for the next impact of the user's
foot
with the traveling surface.
15 Pressure sensing circuitry 120 and control system 300 are mounted to
the shoe and are powered by a common, conventional battery supply. As
pressure sensing device 104 and the fluid system are generally located in the
sole of the shoe, the described electrical connections are preferably embedded
in the upper and the sole of the shoe.
2 o The Figure 11 M embodiment can also be modified to omit the
applicant's concavely rounded sides and can be combined with the various
features of any one or more of the other figures included in this application,
as
can the features of Figures 11N-11P. Pressure sensing devices 104 are also
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~8
shown in Fig. 11 M. A control system 300, such as a microprocessor as
described above, forms part of the embodiment shown in Figure 11 M (and
Figures 11N-110), but is not shown in the frontal plane cross section.
Figure 11N shows the application of the figure 11M concept as
described above and implemented in combination with a removable midsole
section 14~. One significant advantage of this embodiment, besides improved
lateral stability, is that the potentially most expensive component of the
shoe
sole, the removable insert, can be moved to other pairs of shoe upper/bottom
soles, whether new or having a different style or function. Separate removable
insoles can also be useful in this case, especially in changing from athletic
shoes to dress shoes, for function and/or style.
Figure 11N shows a simplified embodiment employing only two
bladders or encapsulated sections 188, each of ~,vhich extends from a
concavely
rounded side to the central portion. Figure 11N is based on the right side of
is Figure 13A.
The Figure 110 embodiment is similar to the Figure 11N embodiment,
except that only one bladder or encapsulated section 188 is shown, separated
centrally by a wall 189 containing a fluid valve communicating bet'veen the
two
separate parts of the section or bladder 188. The angle of the separating wall
2 0 189 provides a gradual transition from the pressure of the left
compartment to
the pressure of the right compartment, but is not required. Other structures
may
be present within or outside the section or bladder 188 for support or other
purposes, as is known in the art.
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Figure 11 P is a perspective view of the applicant's invention, including
the control system 300. such as a microprocessor, and pressure-sensing
circuitry
120, which can be located anywhere in the removable midsole insert 14~
shown, in order for the entire unit to be removable as a single piece, with
placement in the shank proximate the main longitudinal arch of the wearer's
foot shown in this figure, or alternatively, located elsewhere in the shoe,
potentially with a wired or wireless connection and potentially separate means
of attachment. The heel bladder 188 shown in Fig. 11 P is similar to that
shown
in Fig. 11 O with both lateral and medial chambers.
1o Like Figure 11M, Figures 11N-11P operate in the manner known in the
art as described above, except as otherwise shown or described herein by the
applicant, with the applicant's depicted embodiments being preferred but not
required.
Although not shown, the removable midsole section 14~ of the various
1 s embodiments shown in figures 11 A-11 O, can include its own integral upper
or
bootie, such as of elastic incorporating stretchable fabric, and its own outer
sole
for protection of the midsole and for traction, so that the midsole section
145
can be worn, preferably indoors, without the shoe upper 21 and outer sole 149.
Such a removable midsole section 145 can still be inserted into the Figure 11
C
2o upper and sole as described above for outdoor or other rigorous use.
The embodiments shown in Figures 11M-11P can also include the
capability to function sufficiently rapidly to sense an unstable shoe sole
condition such as, for example, that initiating a slip, trip, or fall, and to
react to
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promote a stable or more stable shoe sole condition to attempt to prevent a
fall
or at least attempt to reduce associated injuries, for example, by rapidly
reducing high point pressure in one zone of the shoe sole so that pressures in
all
zones are quickly equalized to restore stability of the shoe sole.
The removable midsole section 145, for example as shown in Figures
11 A-11 P, can also be used in combination with, or to implement, one or more
features of any of the applicant's prior inventions shown in the other figures
in
this application. Such use can also include a combination of features shown in
any other figures of the present application. For example, the removable
1 o midsole section 14~ of the present invention may replace all or any
portion or
portions of the various midsoles, insoles and bottom soles which are shown in
the figures of the present application, and may be combined with the various
other features described in reference to any of these figures in any of these
forms.
15 The removable midsole section 14~ shown in Figures 1 lA-11P can be
integrated into, or may replace any conventional midsole, insert, or portion
thereof. If the removable midsole is used to replace a conventional mass-
market or "over the counter" shoe sole insert, for example, then any of the
features of the conventional insert can be provided by an equivalent feature,
2 o including structural support or cushioning or otherwise, in the removable
midsole section 14~.
Figs. 12A-C show a series of conventional shoe sole cross-sections in the
frontal plane at the heel utilizing both sagittal plane 181 and horizontal
plane
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sipes 182, and in which some or all of the sipes do not originate from any
outer
shoe sole surface, but rather are entirely internal. Relative motion beriveen
internal surfaces is thereby made possible to facilitate the natural
deformation of
the shoe sole.
s Fig. 12A shows a group of three midsole section or lamination layers.
Preferably, the central layer 188 is not glued to the other surfaces in
contact with
it. Instead, those surfaces are internal deformation sipes in the sagittal
plane 181
and in the horizontal plane 182, which encapsulate the central layer 188,
either
completely or partially. The relative motion bet~,-een midsole section layers
at the
1 o deformation sipes 18 l and 182 can be enhanced with lubricating agents,
either
wet like silicone or dry like Teflon, of any degree of viscosity. Shoe sole
materials can be closed cell if necessary to contain the lubricating agent or
a non-
porous surface coating or layer of lubricant can be applied. The deformation
sipes can be enlarged to channels or any other practical geometric shape as
sipes
1 s defined in the broadest possible terms.
The relative motion can be diminished by the use of roughened surfaces
or other conventional methods of increasing the coefficient of friction
between
midsole section layers. If even greater control of the relative motion of the
central
layer 188 is desired, as few as one or many more points can be glued together
2 o anywhere on the internal deformation sipes 181 and 182, making them
discontinuous, and the glue can be any degree of elastic or inelastic.
In Fig. 12A, the outside structure of the sagittal plane deformation sipes
181 is the shoe upper 21, which is typically flexible and relatively elastic
fabric or
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leather. In the absence of any connective outer material like the shoe upper
shown in Fig. 12A, just the outer edges of the horizontal plane deformation
sipes
182 can be glued together.
Fig. 12B shows another conventional shoe sole in frontal plane cross
section at the heel with a combination similar to Fig. 12A of both horizontal
and
sagittal plane deformation sipes that encapsulate a central section 188. Like
Fig.
12A, the Fig. 12B structure allows the relative motion of the central section
188
with its encapsulating outer midsole section 184, which encompasses its sides
as
well as the top surface, and bottom sole 149, both of which are attached at
their
1 o common boundaries 8.
This Fig. 12B approach is analogous to the applicant's fully rounded shoe
sole invention with an encapsulated midsole chamber of a pressure-transmitting
medium like silicone; in this conventional shoe sole case, however, the
pressure-
transmitting medium is a more conventional section of a typical shoe
cushioning
material like PV or EVA, which also provides cushioning.
Fig. 12C is another conventional shoe sole shown in frontal plane cross
section at the heel with a combination similar to Figs. 12A and 12B of both
horizontal and sagittal plane deformation sipes. However, instead of
encapsulating a central section 188, in Fig. 12C an upper section 187 is
partially
2 o encapsulated by deformation sipes so that it acts much like the central
section
188, but is more stable and more closely analogous to the actual structure of
the
human foot.
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The upper section 187 would be analogous to the integrated mass of fatty
pads, which are U-shaped and attached to the calcaneus or heel bone.
Similarly.
the shape of the deformation sipes is U-shaped in Fig. 12C and the upper
section
187 is attached to the heel by the shoe upper, so it should function in a
similar
fashion to the aggregate action of the fatter pads. The major benefit of the
Fig.
12C invention is that the approach is so much simpler and therefore easier and
faster to implement than the highly complicated anthropomorphic design shown
in Fig. 10 above. The midsole sides 18~ shown in Fig. 12C are like the side
portion of the encapsulating midsole 184 in Fig. 12B.
Fig. 12D shows in a frontal plane cross section at the heel a similar
approach applied to the applicant's fully rounded design. Fig. 12D shows a
design including an encapsulating chamber and a variation of the attachment
for
attaching the shoe upper to the bottom sole.
The left side of Fig. 12D shows a variation of the encapsulation of a
m central section 188 shown in Fig. 12B, but the encapsulation is only
partial, with a
center upper section of the central section 188 either attached or continuous
with
the encapsulating outer midsole section 184.
The right side of Fig. 12D shows a structure of deformation sipes like that
of Fig. 12C, with the upper midsole section 187 provided with the capability
of
2 o moving relative to both the bottom sole and the side of the midsole. The
Fig. 12D
structure varies from that of Fig. 12C also in that the deformation sipe 181
in
roughly the sagittal plane is partial only and does not extend to the upper
surface
30 of the midsole 147, as it does Fig. 12C.
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Figures 13A& 13B show, in frontal plane cross section at the heel area,
shoe sole structures like Figs. ~A&B, but in more detail and with the bottom
sole
149 extending relatively farther up the side of the midsole.
The right side of Figs. 13A&13B show the preferred embodiment, which
is a relatively thin and tapering portion of the bottom sole extending up most
of
the midsole and is attached to the midsole and to the shoe upper 21, which is
also
attached preferably first to the upper midsole 147 where both meet at 3 and
then
attached to the bottom sole where both meet at 4. The bottom sole is also
attached to the upper midsole 147 where they join at ~ and to the midsole 148
at
io 6.
The left side of Figs. 13A&13B show a more conventional attachment
arrangement, where the shoe sole is attached to a fully lasted shoe upper 21.
The
bottom sole 149 is attached to: the midsole 148 where their surfaces coincide
at 6,
the upper midsole 147 at ~, and the shoe upper 21 at 4
15 Fig. 13A shows a shoe sole with another variation of an encapsulated
section 188. The encapsulated section 188 is shown bounded by the bottom sole
149 at line 8 and by the rest of the midsole 147 and 148 at line 9 . Fig. 13A
shows more detail than prior figures, including an insole (also called sock
liner) 2,
which is rounded to the shape of the wearer's foot sole, just like the rest of
the
2 o shoe sole, so that the foot sole is supported throughout its entire range
of sideways
motion, from maximum supination to maximum pronation.
The insole 2 overlaps the shoe upper 21 at 13. This approach ensures that
the load-bearing surface of the wearer's foot sole does not come in contact
with
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6~
any seams which could cause abrasions. Although only the heel section is shown
in this figure, the same insole structure would preferably be used elsewhere,
particularly the forefoot. Preferably, the insole would coincide with the
entire
load-bearing surface of the wearer's foot sole, including the front surface of
the
toes, to provide support for front-to-back motion as well as sideways motion.
The Fig. 13 design provides firm flexibility by encapsulating fully or
partially, roughly the middle section of the relatively thick heel of the shoe
sole
(or of other areas of the sole, such as any or all of the essential support
elements
of the foot, including the base of the fifth metatarsal, the heads of the
metatarsals,
1 o and the first distal phalange). The outer surfaces of that encapsulated
section or
sections are allowed to move relatively freely by not gluing the encapsulated
section to the surrounding shoe sole.
Firmness in the Fig. 13 design is provided by the high pressure created
under multiples of body weight loads during locomotion within the encapsulated
i s section or sections, making it relatively hard under extreme pressure,
roughly like
the heel of the foot. Unlike conventional shoe soles, which are relatively
inflexible and thereby create local point pressures, particularly at the
outside edge
of the shoe sole, the Fig. 13 design tends to distribute pressure evenly
throughout
the encapsulated section, so the natural biomechanics of the wearer's foot
sole are
2 o maintained and shearing forces are more effectively dealt with.
In the Fig. 13A design, firm flexibility is provided by encapsulating
roughly the middle section of the relatively thick heel of the shoe sole or
other
areas of the sole, while allowing the outer surfaces of that section to move
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relatively freely by not conventionally Gluing the encapsulated section to the
surrounding shoe sole. Firmness is provided by the high pressure created.under
body weight loads within the encapsulated section, making it relatively hard
under extreme pressure, roughly like the heel of the foot, because it is
surrounded
by flexible but relatively inelastic materials, particularly the bottom sole
149 (and
connecting to the shoe sole upper, which also can be constructed by flexible
and
relatively inelastic material. The same U-shaped structure is thus formed on a
macro level by the shoe sole that is constructed on a micro level in the human
foot
sole, as described definitively by Erich Blechschmidt in Foot and Ankle,
March,
1982.
In summary, the Fig 13A design shows a shoe construction for a shoe,
comprising: a shoe sole with at least one compartment under the structural
elements of the human foot; the compartment containing a pressure-transmitting
medium composed of an independent section of midsole material that is not
firmly attached to the shoe sole surrounding it; pressure from normal load-
bearing
is transmitted progressively at least in part to the relatively inelastic
sides, top and
bottom of said shoe sole compartment, producing tension.
The Fig. 13A design can be combined with the designs shown in Figs. ~8-
60 so that the compartment is surrounded by a reinforcing layer of relatively
2 o flexible and inelastic fiber.
Figs. 13A&13B shows constant shoe sole thickness in frontal plane cross-
sections, but that thickness can vary somewhat (up to roughly 25% in some
cases)
in frontal plane cross-sections. Fig. 13B shows a design just like Fig. 13A,
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except that the encapsulated section is reduced to only the load-bearing
boundary
layer beriveen the midsole 148 and the bottom sole 149. In simple terms, then,
most or all of the upper surface of the bottom sole and the lower surface of
the
midsole are not attached, or at least not firmly attached, where they coincide
at
line 8. The bottom sole and midsole are firmly attached only along the non-
load-
bearing sides of the midsole. This approach is simple and easy. The load-
bearing
boundary layer 8 is like the internal horizontal sipe described in Figure 12
above.
The sipe can be a channel filled with flexible material or it can simply be a
thinner chamber.
The boundary area 8 can be unglued, so that relative motion between the
two surfaces is controlled only by their structural attachment together at the
sides.
In addition, the boundary area can be lubricated to facilitate relative motion
beriveen surfaces or lubricated by a viscous liquid that restricts motion. Or
the
boundary area 8 can be glued with a semi-elastic or semi-adhesive glue that
~ 5 controls relative motion but still permits some motion. The semi-elastic
or semi-
adhesive glue would then serve a shock absorption function as well.
In summary, the Fig 13B design shows a shoe construction for a shoe,
comprising: a shoe upper and a shoe sole that has a bottom portion with sides
that are relatively flexible and inelastic; at least a portion of the bottom
sole sides
2 o firmly attach directly to the shoe upper; a shoe upper that is composed of
material
that is flexible and relatively inelastic at least where the shoe upper is
attached to
the bottom sole; the attached portions enveloping the other sole portions of
the
shoe sole; and the shoe sole having at least one horizontal boundary area
serving
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as a sipe that is contained internally w,~ithin the shoe sole. The Fig 13B
design can
be combined with Figs. ~8-60 to include a shoe sole bottom portion composed of
material reinforced W th at least one fiber layer that is relatively flexible
and
inelastic and that is oriented in the horizontal plane;
Figs. 14, 1 ~, and 16 show frontal plane cross sectional views of a shoe
sole according to the applicant's prior inventions based on the Theoretically
Ideal
Stability Plane, taken at about the ankle joint to show the heel section of
the shoe.
Figs. 17 through 26 show the same view of the applicant's enhancement of that
invention. In the figures, a foot 27 is positioned in a naturally rounded shoe
having an upper 21 and a rounded shoe sole 28. The shoe sole normally contacts
the ground 43 at about the lower central heel portion thereof., as shown in
Fig. 17.
The concept of the Theoretically Ideal Stability Plane defines the plane S 1
in
terms of a locus of points determined by the thickness(es) of the sole.
Fig. 14 shows, in a rear cross sectional view, the inner surface of the shoe
15 sole conforming to the natural contour of the foot and the thickness of the
shoe
sole remaining constant in the frontal plane, so that the outer surface
coincides
with the theoretically ideal stability plane.
Fig. 1~ shows a fully rounded shoe sole design that follows the natural
contour of all of the foot, the bottom as well as the sides, while retaining a
2 o constant shoe sole thickness in the frontal plane.
The fully rounded shoe sole assumes that the resulting slightly rounded
bottom when unloaded will deform under load and flatten just as the human foot
bottom is slightly rounded unloaded but flattens under load. Therefore, the
shoe
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sole material must be of such composition as to allow the natural deformation
following that of the foot. The design applies particularly to the heel, but
to the
rest of the shoe sole as well. By providing the closest match to the natural
shape
of the foot, the fully rounded design allows the foot to function as naturally
as
possible. Under load, Fig. 1 ~ would deform by flattening to look essentially
like
Fig. 14. Seen in this light, the naturally rounded side design in Fig. 14 is a
more
conventional, conservative design that is a special case of the more general
fully
rounded design in Fig. 1 ~, which is the closest to the natural form of the
foot, but
the least conventional. The amount of deformation flattening used in the Fig.
14
1 o design. which obviously varies under different loads. is not an essential
element
of the applicant's invention.
Figs. 14 and 15 both show in frontal plane cross-sections the Theoretically
Ideal Stability Plane, which is also theoretically ideal for efficient natural
motion
of all kinds, including running, jogging or walling. Fig. 1 ~ shows the most
15 general case, the fully rounded design, which conforms to the natural shape
of the
unloaded foot. For any given individual, the Theoretically Ideal Stability
Plane
S 1 is determined, first, by the desired shoe sole thickness(es) in a frontal
plane
cross section, and, second, by the natural shape of the individual's foot
surface 29.
For the special case shown in Fig. 14, the Theoretically Ideal Stability
2 o Plane for any particular individual (or size average of individuals) is
determined,
first, by the given frontal plane cross section shoe sole thickness(es);
second, by
the natural shape of the individual's foot; and, third, by the frontal plane
cross-
section width of the individual's load-bearing footprint 30b, which is defined
as
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the upper surface of the shoe sole that is in physical contact with and
supports the
human foot sole.
The Theoretically Ideal Stability Plane for the special case is composed
conceptually of two parts. Shown in Fig. 14, the first part is a line segment
31 b of
equal length and parallel to line 30b at a constant distances) equal to shoe
sole
thickness. This corresponds to a conventional shoe sole directly underneath
the
human foot, and also corresponds to the flattened portion of the bottom of the
load-bearing shoe sole 28b. The second part is the naturally rounded stability
side
outer edge 31 a located at each side of the first part, line segment 31 b.
Each point
10 on the rounded side outer edge 31 a is located at a distance which is
exactlv the
shoe sole thickness (s) from the closest point on the rounded side inner edge
30a.
In summary, the Theoretically Ideal Stability Plane is used to determine a
geometrically precise bottom contour of the shoe sole based on a top contour
that
conforms to the contour of the foot.
s It can be stated unequivocally that any shoe sole contour, even of similar
contour, that exceeds the Theoretically Ideal Stability Plane will restrict
natural
foot motion, while any less than that plane will degrade natural stability, in
direct
proportion to the amount of the deviation. The theoretical ideal was taken to
be
that which is closest to natural.
2 o Fig. 16 illustrates in frontal plane cross-section another variation of a
shoe
sole that uses stabilizing quadrants 26 at the outer edge of a conventional
shoe
sole 28b illustrated generally at the reference numeral 28. The stabilizing
quadrants would be abbreviated in actual embodiments.
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Fig. 17 illustrates the shoe sole side thickness increasing beyond the
Theoretically Ideal Stability Plane to increase stability somewhat beyond its
natural level. The unavoidable trade-off which results is that natural motion
would be restricted somewhat and the weight of the shoe sole would increase
somewhat.
Fig. 17 shows a situation wherein the thickness of the sole at each of the
opposed sides is thicker at the portions of the sole 31a by a thickness which
gradually varies continuously from a thickness (s) through a thickness (s+sl),
to a
thickness (s+s2). These designs recognize that lifetime use of existing shoes,
the
1 o design of which has an inherent flaw that continually disrupts natural
human
biomechanics, has produced thereby actual structural changes in a human foot
and
ankle to an extent that must be compensated for. Specifically, one of the most
common of the abnormal effects of the inherent existing flaw is a weakening of
the long arch of the foot, increasing pronation. These designs therefore
provide
1 s greater than natural stability and should be particularly useful to
individuals,
generally with low arches, prone to pronate excessively, and could be used
only
on the medial side. Similarly, individuals with high arches and a tendency to
over
supinate and who are vulnerable to lateral ankle sprains would also benefit,
and
the design could be used only on the lateral side. A shoe for the general
2 o population that compensates for both weaknesses in the same shoe would
incorporate the enhanced stability of the design compensation on both sides.
Fig. 17, like Figs. 14 and 1 S, shows an embodiment which allows the shoe
sole to deform naturally, closely paralleling the natural deformation of the
bare
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foot under load. In addition, shoe sole material must be of such composition
as to
allow natural deformation similar to that of the foot.
This design retains the concept of contouring the shape of the shoe sole to
the shape of the human foot. The difference is that the shoe sole thickness in
the
frontal plane is allowed to vary rather than remain uniformly constant. More
specifically, Figs. 17, 18, 19, 20, and 24 show, in frontal plane cross
sections at
the heel, that the shoe sole thickness can increase beyond the theoretically
ideal
stability- plane ~ l, in order to provide greater than natural stability. Such
variations (and the following variations) can be consistent through all
frontal
plane cross sections, so that there are proportionately equal increases to the
theoretically ideal stability plane ~ 1 from the front of the shoe sole to the
back.
Alternatively, the thickness can vary, preferably continuously, from one
frontal
plane to the next.
The exact amount of the increase in shoe sole thickness beyond the
1 s theoretically ideal stability plane is to be determined empirically.
Ideally, right
and left shoe soles would be custom designed for each individual based on a
biomechanical analysis of the extent of his or her foot and ankle dysfunction
in
order to provide for optimal support. It is expected that any such custom
designed shoes would generally have a thickness exceeding the Theoretically
2 o Ideal Stability Plane by an amount up to ~ or 10 percent. However, the
thickness
could exceed the Theoretically Ideal Stability Plane by an amount up to 25
percent. The optimal contour for the increased thickness may also be
determined
empirically.
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Fig. 18 shows a variation of the enhanced fully rounded design wherein
the shoe sole begins to thicken beyond the theoretically ideal stability plane
~ 1
somewhat offset to the sides.
Fig. 19 shows a thickness variation which is symmetrical as in the case of
Fig. 17 and 18, but wherein the shoe sole begins to thicken beyond the
Theoretically Ideal Stability Plane ~ 1 directly underneath the foot heel 27
on
about a center line of the shoe sole. In fact, in this case the thickness of
the shoe
sole is the same as the Theoretically Ideal Stability Plane only at that
beginning
point underneath the upright foot. For the embodiment wherein the shoe sole
c thickness varies, the Theoretically Ideal Stability Plane is determined by
the least
thickness in the shoe sole's direct load-bearing portion meaning that portion
with
direct tread contact on the ground. The outer edge or periphery' of the shoe
sole is
obviously excluded, since the thickness there always decreases to zero. Note
that
the capability of the design to deform naturally may make some portions of the
15 shoe sole load-bearing when they are actually under a load, especially
walking or
naming, even though they may not be when the shoe sole is not under a load.
Fig. 20 shows that the thickness can also increase and then decrease.
Other thickness variation sequences are also possible. The variation in side
contour thickness can be either symmetrical on both sides or asymmetrical,
2 o particularly with the medial side providing more stability than the
lateral side,
although many other asymmetrical variations are possible. Also, the pattern of
the right foot can vary from that of the left foot.
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Figs. 21, 22. 23 and 2~ show that similar variations in shoe midsole (other
portions of the shoe sole area not shown) density can provide similar, but
reduced, effects to the variations in shoe sole thickness described previously
in
Figs. 17-20. The major advantage of this approach is that the structural
Theore-
tically Ideal Stability Plane is retained, so that naturally optimal stability
and
efficient motion are retained to the maximum extent possible.
The forms of dual and tri-density midsoles shown in the figures are
extremely common in the current art of athletic shoes, and any number of
densities are theoretically possible, although an angled alternation of just
rivo
1 o densities like that shown in Fia. 21 provides continually changing
composite
density. However, mufti-densities in the midsole were not preferred since only
a
uniform density provides a neutral shoe sole design that does not interfere
with
natural foot and ankle biomechanics in the way that mufti-density shoe soles
do,
which is by providing different amounts of support to different parts of the
foot.
v s In these fiwres, the density of the sole material designated by the legend
(d~) is
firmer than (d) while (d') is the firmest of the three representative
densities
shown. In Fig. 21, a dual density sole is shown, with (d) having the less fum
density.
It should be noted that shoe soles using a combination both of sole
2 o thicknesses greater than the Theoretically Ideal Stability Plane and of
midsole
density variations like those just described are also possible but not shown.
Fig. 26 shows a bottom sole tread design that provides about the same
overall shoe sole density variation as that provided in Fig. 23 by midsole
density
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variation. The less supporting tread there is under any particular portion of
the
shoe sole, the less effective overall shoe sole density there is, since the
midsole
above that portion will deform more easily than if it were fully supported.
Fig. 27 shows embodiments like those in Figs. 17 through 26 but wherein
a portion of the shoe sole thickness is decreased to less than the
theoretically ideal
stability plane. It is anticipated that some individuals with foot and ankle
biomechanics that have been degraded by existing shoes may benefit from such
embodiments, which would provide less than natural stability but greater
freedom
of motion, and less shoe sole weight and bulk. In particular, it is
anticipated that
1 o individuals with overly rigid feet, those with restricted range of motion,
and those
tending to over-supinate may benefit from the Fig. 14 embodiments. Even more
particularly, it is expected that the invention will benefit individuals with
significant bilateral foot function asymmetry: namely, a tendency toward
pronation on one foot and supination on the other foot. Consequently, it is
antici-
pated that this embodiment would be used only on the shoe sole of the
supinating
foot, and on the inside portion only, possibly only a portion thereof. It is
expected
that the range less than the Theoretically Ideal Stability Plane would be a
maximum of about five to ten percent, though a maximum of up to twrenty-five
percent may be beneficial to some individuals.
2 o Fig. 27A shows an embodiment like Figs. 17 and 20, but with naturally
rounded sides less than the Theoretically Ideal Stability Plane. Fig. 27B
shows an
embodiment like the fully rounded design in Figs. 18 and 19, but with a shoe
sole
thickness decreasing with increasing distance from the center portion of the
sole.
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Fig. 27C shows an embodiment like the quadrant-sided design of Fig. 24, but
with the quadrant sides increasingly reduced from the Theoretically Ideal
Stability
Plane.
The lesser-sided design of Fig. 27 would also apply to the Figs. 21-3 and
2~ density variation approach and to the Fig. 26 approach using tread design
to
approximate density variation.
Fig. 28A-28C show, in cross-sections that with the quadrant-sided design
of Figs. 16, 24, 2~ and 27C that it is possible to have shoe sole sides that
are both
greater and lesser than the theoretically ideal stability plane in the same
shoe. The
1 o radius of an intermediate shoe sole thickness, taken at (s'') at the base
of the fifth
metatarsal in Fig. 28B, is maintained constant throughout the quadrant sides
of
the shoe sole, including both the heel, Fig. 28C, and the forefoot, Fig. 28A,
so that
the side thickness is less than the Theoretically Ideal Stability Plane at the
heel
and more at the forefoot. Though possible, this is not a preferred approach.
1 s The same approach can be applied to the naturally rounded sides or fully
rounded designs described in Figs. 14, 1 ~, 17-23 and 26, but it is also not
preferred. In addition, as shown in Figs. 28D-28F, it is possible to have shoe
sole
sides that are both greater and lesser than the Theoretically Ideal Stability
Plane in
the same shoe, like Figs. 28A-28C, but wherein the side thickness (or radius)
is
2o neither constant like Figs 28A-28C or varying directly with shoe sole
thickness,
but instead varying quite indirectly with shoe sole thickness. As shown in
Figs
28D-28F, the shoe sole side thickness varies from somewhat less than the shoe
sole thickness at the heel to somewhat more at the forefoot. This approach,
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though possible, is again not preferred, and can be applied to the quadrant
sided
design, but is not preferred there either.
Fig. 29 shows in a frontal plane cross-section at the heel (center of ankle
joint) the general concept of a shoe sole 28 that conforms to the natural
shape of
the human foot 27 and that has a constant thickness (s) in frontal plane cross
sections. The surface 29 of the bottom and sides of the foot 27 should
correspond
exactly to the upper surface 30 of the rounded shoe sole 28. The shoe sole
thickness is defined as the shortest distance (s) between any point on the
upper
surface 30 of the rounded shoe sole 28 and the lower surface 31. In effect,
the
1 o applicant's general concept is a rounded shoe sole 28 that waps around and
conforms to the natural contours of the foot 27 as if the rounded shoe sole 28
were made of a theoretical single flat sheet of shoe sole material of uniform
thickness, wrapped around the foot with no distortion or deformation of that
sheet
as it is bent to the foot's contours. To overcome real world deformation
problems
15 associated with such bending or wrapping around contours, actual
construction of
the shoe sole contours of uniform thickness will preferably involve the use of
multiple sheet lamination or injection molding techniques.
Figs. 30A, 30B, and 30C illustrate in frontal plane cross-section use of
naturally rounded stabilizing sides 28a at the outer edge of a shoe sole 28b
2 o illustrated generally at the reference numeral 28. This eliminates the
unnatural
sharp bottom edge, especially of flared shoes, in favor of a naturally rounded
shoe
sole outside 31 as shown in Fig. 29. The side or inner edge 30a of the shoe
sole
stability side 28a is rounded like the natural form on the side or edge of the
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human foot, as is the outside or outer edge 31 a of the shoe sole stability
side 28a
to follow a theoretically ideal stability plane. The thickness (s) of the
rounded
shoe sole 28 is maintained exactly constant, even if the shoe sole is tilted
to either
side, or forward or backward. Thus, the naturally rounded stabilizing sides
28a,
are defined as the same as the thickness 33 of the shoe sole 28 so that, in
cross-
section, the shoe sole comprises a stable rounded shoe sole 28 having at its
outer
edge naturally rounded stabilizing sides 28a with a surface 31 a representing
a
portion of a Theoretically Ideal Stability Plane and described by naturally
rounded
sides equal to the thickness (s) of the rounded shoe sole 28. The top of the
shoe
1 o sole 30b coincides with the shoe wearer's load-bearing footprint, since in
the case
shown the shape of the foot is assumed to be load-bearing and therefore flat
along
the bottom. A top edge 32 of the naturally rounded stability side 28a can be
located at any point along the rounded side of the outer surface of the foot
29,
while the inner edge 33 of the naturally rounded side 28a coincides with the
15 perpendicular sides 34 of the load-bearing shoe sole 28b. In practice, the
rounded
shoe sole 28 is preferably integrally formed from the portions 28b and 28a.
Thus,
the Theoretically Ideal Stability Plane includes the contours 31 a merging
into the
lower surface 31 b of the rounded shoe sole 28.
Preferably, the peripheral extent 36 of the load-bearing portion of the sole
20 28b of the shoe includes all of the support structures of the foot but
extends no
further than the outer edge of the foot sole 37 as defined by a load-bearing
footprint, as shown in Fig. 30D, which is a top view of the upper shoe sole
surface 30b. Fig. 30D thus illustrates a foot outline at numeral 37 and a
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recommended sole outline 36 relative thereto. Thus, a horizontal plane outline
of
the top of the load-bearing portion of the shoe sole. therefore exclusive of
rounded stability sides, should, preferably-, coincide as nearly as
practicable with
the load-bearing portion of the foot sole with which it comes into contact.
Such a
horizontal outline, as best seen in Figs. 30D and 33D, should remain uniform
throughout the entire thickness of the shoe sole eliminating negative or
positive
sole flare so that the sides are exactly perpendicular to the horizontal plane
as
shown in Fig. 30B. Preferably, the density of the shoe sole material is
uniform.
As shown diagrammatically in Fig. 31, preferably, as the heel lift or
wedge 38 of thickness (s 1 ) increases the total thickness (s + s 1 ) of the
combined
midsole and outersole 39 of thickness (s) in an aft direction of the shoe, the
naturally rounded sides 28a increase in thickness exactly the same amount
according to the principles discussed in connection with Fig. 30. Thus, the
thick-
ness of the inner edge 33 of the naturally rounded side is always equal to the
m constant thickness (s) of the load-bearing shoe sole 28b in the frontal
cross-
sectional plane.
As shown in Fig. 31B, for a shoe that follows a more conventional
horizontal plane outline, the sole can be improved significantly by the
addition of
a naturally rounded side 28a which correspondingly varies with the thickness
of
2o the shoe sole and changes in the frontal plane according to the shoe heel
lift 38.
Thus, as illustrated in Fig. 31B, the thickness of the naturally rounded side
28a in
the heel section is equal to the thickness (s + sl) of the rounded shoe sole
28
which is thicker than the shoe sole 39 thickness (s) shown in Fig. 3 lA by an
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amount equivalent to the heel lift 38 thickness (sl). In the generalized case.
the
thickness (s) of the rounded side is thus always equal to the thickness (s) of
the
shoe sole.
Fig. 32 illustrates a side cross-sectional view of a shoe to which the
invention has been applied and is also shown in a top plane view in Fig. 33.
Thus. Figs. 33A, 33B, and 33C represent frontal plane cross-sections
taken along the forefoot, at the base of the fifth metatarsal, and at the
heel, thus
illustrating that the shoe sole thickness is constant at each frontal plane
cross-
section. even though that thickness vanes from front to back, due to the heel
lift
c 38 as shown in Fig. 32, and that the thickness of the naturally rounded
sides is
equal to the shoe sole thickness in each Fig. 33A-33C cross section. Moreover,
in
Fig. 33D, a horizontal plane overview of the left foot, it can be seen that
the
contour of the sole follows the preferred principle in matching, as nearly as
practical, the load-bearing sole print shown in Fia. 30D.
Fig. 34 illustrates an embodiment of the invention which utilizes varying
portions of the Theoretically Ideal Stability Plane ~ 1 in the naturally
rounded
sides 28a in order to reduce the weight and bulk of the sole, while accepting
a
sacrifice in some stability of the shoe. Thus, Fig. 34A illustrates the
preferred
embodiment as described above in connection with Fig. 31 wherein the outer
2 o edge 31 a of the naturally rounded sides 28a follows a Theoretically Ideal
Stability Plane ~ 1. As in Figs. 29 and 30, the rounded surfaces 31 a, and the
lower
surface of the sole 31b lie along the Theoretically Ideal Stability Plane 51.
As
shown in Fig. 34B, an engineering trade-off results in an abbreviation within
the
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Theoretically Ideal Stability Plane ~ 1 by forming a naturally rounded side
surface
~3a approximating the natural contour of the foot (or more Geometrically
regular,
which is less preferred) at an angle relative to the upper plane of the
rounded shoe
sole 28 so that only a smaller portion of the rounded side 28a defined by the
constant thickness lying alone the surface 31 a is coplanar with the
Theoretically
Ideal Stability Plane ~ 1. Figs. 34C and 34C show similar embodiments wherein
each engineering trade-off shown results in progressively smaller portions of
rounded side 28a, which lies along the Theoretically Ideal Stability Plane 51.
The
portion of the surface 3 la merges into the upper side surface ~3a of the
naturally
rounded side 28a.
The embodiment of Fig. 34 may be desirable for portions of the shoe sole
which are less frequently used so that the additional part of the side is used
less
frequently. For example, a shoe may typically roll out laterally, in an
inversion
mode, to about 20° on the order of 100 times for each single time it
rolls out to
5 40°. For a basketball shoe, shown in Fig. 34B, the extra stability is
needed. Yet,
the added shoe weight to cover that infrequently experienced range of motion
is
about equivalent to covering the frequently encounter range. Since, in a
racing
shoe this weight might not be desirable, an engineering trade-off of the type
shown in Fig. 34D is possible. A typical athletic/jogging shoe is shown in
Fig.
20 34C. The range of possible variations is limitless.
Fig. 3~ shows the Theoretically Ideal Stability Plane ~ 1 in defining
embodiments of the shoe sole having differing tread or cleat patterns. Thus,
Fig.
3~ illustrates that the invention is applicable to shoe soles having
conventional
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bottom treads. Accordingly, Fia. 3JA is similar to Fia. 34B further including
a
tread portion 60, while Fig. 3~B is also similar to Fig. 34B wherein the sole
includes a cleated portion 61. The surface 63 to which the cleat bases are
affixed
should preferably be on the same plane and parallel the theoretically ideal
stability
plane ~ 1, since in soft ground that surface rather than the cleats become
load-
bearing. The embodiment in Fia. 3~C is similar to Fig. 34C showing still an
alternative tread construction 62. In each case, the load-bearing outer
surface of
the tread or 'cleat pattern 60-62 lies along the Theoretically Ideal Stability
Plane
~l.
i o Fig. 36 illustrates in a curve 70 the range of side to side
inversion/eversion
motion of the ankle center of gravit<- 71 from the shoe shown in frontal plane
cross-section at the ankle. Thus, in a static case where the center of gravity
71
lies at approximately the mid-point of the sole, and assuming that the shoe
inverts
or everts from 0° to 20° to 40°, as shown in progressions
36A, 36B and 36C, the
locus of points of motion for the center of gravity thus defines the curve 70
wherein the center of gravity 71 maintains a steady level motion with no
vertical
component through 40° of inversion or eversion. For the embodiment
shown, the
shoe sole stability equilibrium point is at 28° (at point 74) and in no
case is there a
pivoting edge to define a rotation point. The inherently superior side to side
2 o stability of the design provides pronation control (or eversion), as well
as lateral
(or inversion) control. In marked contrast to conventional shoe sole designs,
this
shoe design creates virtually no abnormal torque to. resist natural
inversion/eversion motion or to destabilize the ankle joint.
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Fig. 37 thus compares the range of motion of the center of gravity for the
invention, as shown in curve 70. in comparison to cur~~e 80 for the
conventional
wide heel flare and a curve 82 for a narrow rectangle the width of a human
heel.
Since the shoe stability limit is 28° in the inverted mode, the shoe
sole is stable at
the 20° approximate bare foot inversion limit. That factor, and the
broad base of
support rather than the sharp bottom edge of the prior art, make the contour
design stable even in the most extreme case as shown in Fias. 36A-36C and
permit the inherent stability of the bare foot to dominate without
interference,
unlike existing designs, by providing constant, unvarying shoe sole thickness
in
~ o frontal plane cross sections. The stability superiority of the rounded
side design is
thus clear when observing how much flatter its center of gravity curve 70 is
than
in existing popular wide flare design 80. The curve demonstrates that the
rounded side design has significantly more efficient natural 7°
inversion/eversion
motion than the narrow rectangle design the width of a human heel, and very
i 5 much more efficient than the conventional wide flare design. At the same
time,
the rounded side design is more stable in extremis than either conventional
design
because of the absence of destabilizing torque.
Figs. 38A-38D illustrate, in frontal plane cross sections, the naturally
rounded sides design extended to the other natural contours underneath the
load-
2 o bearing foot, such as the main longitudinal arch, the metatarsal (or
forefoot) arch,
and the ridge between the heads of the metatarsals (forefoot) and the heads of
the
distal phalanges (toes). As shown, the shoe sole thickness remains constant as
the
contour of the shoe sole follows that of the sides and bottom of the load-
bearing
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8=1
foot. Fig. 38E shows a sagittal plane cross section of the shoe sole
conforming to
the contour- of the bottom of the load-bearing foot. with thickness varying
according to the heel lift 38. Fig. 38F shows a horizontal plane top view of
the
left foot that shows the areas 8~ of the shoe sole that correspond to the
flattened
portions of the foot sole that are in contact with the ground when load-
bearing.
Contour lines 86 and 87 show approximately the relative height of the shoe
sole
contours above the flattened load-bearing areas 8~ but within roughly the
peripheral extent 3~ of the upper surface of sole 30 shown in Fig. 30. A
horizontal plane bottom view (not shown) of Fig. 38F would be the exact
recipro-
cal or converse of Fig. 38F (i.e. peaks and valleys contours would be exactly
reversed).
Figs. 39A-39D show, in frontal plane cross sections, the fully rounded
shoe sole design extended to the bottom of the entire non-load-bearing foot.
Fig.
39E shows a sagittal plane cross section. The shoe sole contours underneath
the
15 foot are the same as Figs. 38A-38E except that there are no flattened areas
corresponding to the flattened areas of the load-bearing foot. The exclusively
rounded contours of the shoe sole follow those of the unloaded foot. A heel
lift
38 and a midsole and outersole 39, the same as that of Fig. 38, is
incorporated in
this embodiment, but is not shown in Fig. 39.
2 o Fig. 40 shows the horizontal plane top view of the left foot corresponding
to the fully rounded design described in Figs. 39A-39E, but abbreviated along
the
sides to only essential structural support and propulsion elements. Shoe sole
material density can be increased in the unabbreviated essential elements to
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8~
compensate for increased pressure loading there. The essential structural
support
elements are the base and lateral W berosiy of the calcaneus 9~. the heads of
the
metatarsals 96, and the base of the fifth metatarsal 97. They must be
supported
both underneath and to the outside for stability. The essential propulsion
element
is the head of first distal phalange 98. The medial (inside) and lateral
(outside)
sides supporting the base of the calcaneus are shown in Fig. 40 oriented
roughly
along either side of the horizontal plane subtalar ankle joint axis, but can
be
located also more conventionally along the longitudinal axis of the shoe sole.
Fig. 40 shows that the naturally rounded stability sides need not be used
except in
_ " the identified essential areas. Weight savings and flexibility
improvements can be
made by omitting the non-essential stability sides. Contour lines 8~ through
89
show approximately the relative height of the shoe sole contours writhin
roughly
the peripheral extent 3~ of the undeformed upper surface of shoe sole 30 shown
in Fig. 17. A horizontal plane bottom view (not shown) of Fig. 40 would be the
1 ~ exact reciprocal or converse of Fig. 40 (i.e. peaks and valleys contours
would be
exactly reversed).
Fig. 41A shows a development of street shoes with naturally rounded sole
sides incorporating features according to the present invention. Fig. 41 A
develops a Theoretically Ideal Stability Plane ~ 1, as described above, for
such a
2 o street shoe. wherein the thickness of the naturally rounded sides equals
the shoe
sole thickness. The resulting street shoe with a correctly rounded sole is
thus
shown in frontal plane heel cross section in Fig. 41A, with side edges
perpendicular to the ground, as is typical. Fig. 41 B shows a similar street
shoe
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W th a fully rounded design, including the bottom of the sole. accordingly,
the
invention can be applied to an unconventional heel lift shoe, like a simple
wedge,
or to the most conventional design of a typical walking shoe with its heel
separated from the forefoot by a hollow under the instep. The invention can be
applied just at the shoe heel or to the entire shoe sole. With the invention,
as so
applied, the stability and natural motion of any existing shoe design, except
high
heels or spike heels, can be significantly improved by the naturally rounded
shoe
sole design.
Fig. 42 shows a non-optimal but interim or low cost approach to shoe sole
i o construction, whereby the midsole 148 and heel lift 38 are produced
conventionally, or nearly so (at least leaving the midsole bottom surface
flat,
though the sides can be rounded), while the bottom or outer sole 149 includes
most or all of the special contours of the design. Not only would that
completely
or mostly limit the special contours to the bottom sole. which would be molded
specially, it would also ease assembly, since two flat surfaces of the bottom
of the
midsole and the top of the bottom sole could be mated together with less
difficulty than two rounded surfaces, as would be the case otherwise.
The advantage of this approach is seen in the naturally rounded design
example illustrated in Fig. 42A, which shows some contours on the relatively
2 o softer midsole sides, which are subject to less wear but benefit from
greater trac-
tion for stability and ease of deformation, while the relatively harder
rounded
bottom sole provides good wear for the load-bearing areas.
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~7
Fir. 42B shows in a quadrant side design the concept applied to
conventional street shoe heels, which are usually separated from the forefoot
by a
hollow instep area under the main longitudinal arch.
Fig. 42C shows in frontal plane cross-section the concept applied to the
quadrant sided or single plane design and indicating in Fig. 42D in the shaded
area 129 of the bottom sole that portion which should be honeycombed (axis on
the horizontal plane) to reduce the density of the relatively hard outer sole
to that
of the midsole material to provide for relatively uniform shoe density.
Generally, insoles or sock liners should be considered structurally and
functionally as part of the shoe sole, as should any shoe material beriveen
foot and
ground, like the bottom of the shoe upper in a slip-lasted shoe or the board
in a
board-lasted shoe.
Fig. 43 shows in a real illustration a foot 27 in position for a new
biomechanical test that is the basis for the discovery that ankle sprains are
in fact
unnatural for the bare foot. The test simulates a lateral ankle sprain, where
the
foot 27 - on the ground 43 - rolls or tilts to the outside, to the extreme end
of its
normal range of motion, which is usually about 20 degrees at the outer surface
of
the foot 29, as shown in a rear view of a bare (right) heel in Fig. 43.
Lateral
(inversion) sprains are the most common ankle sprains, accounting for about
2 o three-fourths of all ankle sprains.
The especially novel aspect of the testing approach is to perform the ankle
spraining simulation while standing stationary-. The absence of forward motion
is
the key to the dramatic success of the test because otherwise it is impossible
to
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recreate for testing purposes the actual foot and ankle motion that occurs
during a
lateral ankle sprain. and simultaneously to do it in a controlled manner,
while at
normal running speed or even jogging slowly, or walking. 'Vithout the critical
control achieved by slowing forward motion all the w-ay down to zero, any test
subject would end up with a sprained ankle.
That is because actual running in the real w ~orld is dyamic and involves a
repetitive force maximum of three times one's full body weight for each
footstep.
with sudden peaks up to roughly five or six times for quick stops, missteps.
and
direction changes, as might be experienced when spraining an ankle. In
contrast,
o in the static simulation test, the forces are tightly controlled and
moderate, ranging
from no force at all up to whatever maximum amount that is comfortable.
The Stationary Sprain Simulation Test (SSST) consists simply of standing
stationary with one foot bare and the other shod with any shoe. Each foot
alternately is carefully tilted to the outside up to the extreme end of its
range of
i 5 motion, simulating a lateral ankle sprain.
The SSST clearly identifies what can be no less than a fundamental flaw
in existing shoe design. It demonstrates conclusively- that nature's
biomechanical
system. the bare foot, is far superior in stability to man's artificial shoe
design.
Unfortunately, it also demonstrates that the shoe's severe instability
overpowers
2 o the natural stability of the human foot and synthetically creates a
combined
biomechanical system that is artificially unstable. The shoe is the weak link.
The test shows that the bare foot is inherently stable at the approximate 20
degree end of normal joint range because of the wide. steady foundation the
bare
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heel 29 provides the ankle joint, as seen in Fig. =13. In fact, the area of
physical
contact of the bare heel 29 with the ground 43 is not much less when tilted
all the
way out to 20 degrees as when upright at 0 degrees.
The SSST provides a natural yardstick, totally missing until now, to
determine whether any given shoe allows the foot within it to function
naturally.
If a shoe cannot pass this simple test, it is positive proof that a particular
shoe is
interfering with natural foot and ankle biomechanics. The only question is the
exact extent of the interference beyond that demonstrated by the SSST.
Conversely, the applicant's designs employ shoe soles thick enough to
provide cushioning (thin-soled and heel-less moccasins do pass the test, but
do
not provide cushioning and only moderate protection) and naturally stable
performance, like the bare foot, in the SSST.
Fig. 44 shows that, in complete contrast the foot equipped with a
conventional athletic shoe, designated generally by the reference numeral 20
and
having an upper 21, though initially very stable while resting completely flat
on
the ground, becomes immediately unstable when the shoe sole 22 is tilted to
the
outside. The tilting motion lifts from contact with the ground all of the shoe
sole
22 except the artificially sharp edge of the bottom outside comer. The shoe
sole
instability increases the farther the foot is rolled laterally. Eventually,
the
2 o instability induced by the shoe itself is so great that the normal load-
bearing
pressure of full body weight would actively force an ankle sprain, if not
controlled. The abnormal tilting motion of the shoe does not stop at the bare
foot's natural 20 degree limit, as can be seen from the 4~ de~ee tilt of the
shoe
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heel in Fig. 44.
That continued ourivard rotation of the shoe past 20 degrees causes the
foot to slip within the shoe, shifting its position within the shoe to the
outside
edge, further increasing the shoe's structural instability. The slipping of
the foot
within the shoe is caused by the natural tendency of the foot to slide down
the
typically flat surface of the tilted shoe sole; the more the tilt, the
stronger the
tendency. The heel is shown in Fig. 44 because of its primary importance in
sprains due to its direct physical connection to the ankle ligaments that are
tom in
an ankle sprain and also because of the heel's predominant role within the
foot in
1 o bearing body weight.
It is easy to see in the two figures, Figures 43 and 44, how totally different
the physical shape of the natural bare foot is compared to the shape of the
artificial, conventional shoe sole. It is strikingly odd that the rivo
objects, which
apparently both have the same biomechanical function, have completely
different
physical shapes. Moreover, the shoe sole clearly does not deform the same wav
the human foot sole does, primarily as a consequence of its dissimilar shape.
Figs. 45A-45C illustrate clearly the principle of natural deformation as it
applies to the applicant's designs, even though design diagrams like those
preceding are normally shown in an ideal state, without any functional
2 o deformation, obviously to show their enact shape for proper construction.
That
natural structural shape, with its contour paralleling the foot, enables the
shoe sole
to deform naturally like the foot. The natural deformation feature creates
such an
important functional advantage it will be illustrated and discussed here
fully.
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Note in the figures that even when the shoe sole shape is deformed, the
constant
shoe sole thickness in the frontal plane feature of the invention is
maintained.
Fig. 4~A shows upright, unloaded and therefore undeformed the fully
rounded shoe sole design indicated in Fig. 1 ~ above. Fig. 4~A shows a fully
rounded shoe sole design that follows the natural contour of all of the foot
sole,
the bottom as well as the sides. The fully rounded shoe sole assumes that the
resulting slightly rounded bottom when unloaded will deform under load as
shown in Fig. 4~B and flatten just as the human foot bottom is slightly
rounded
unloaded but flattens under load, like Figure 14 above. Therefore, the shoe
sole
material must be of such composition as to allow the natural deformation
following that of the foot. The design applies particularly to the heel, but
to the
rest of the shoe sole as well. By providing the closest possible match to the
natural shape of the foot, the fully rounded design allows the foot to
function as
naturally as possible. Under load, Fig. 4~A would deform by flattening to look
? s essentially like Fig. 4~B.
Figs. 4~A and 4~B show in frontal plane cross-section the Theoretically
Ideal Stability Plane which is also theoretically ideal for efficient natural
motion
of all kinds, including running, jogging or walking. For any given individual,
the
Theoretically Ideal Stability Plane ~ 1 is determined, first, by the desired
shoe sole
2 o thickness (s) in a frontal plane cross section, and, second, by the
natural shape of
the individual's foot surface 29.
For the case shown in Fig. 45B, the Theoretically Ideal Stability Plane for
any particular individual (or size average of individuals) is determined,
first, by
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the given frontal plane cross-section shoe sole thickness (s); second, by the
natlu-al shape of the individual's foot;. and, third, by the frontal plane
cross section
width of the individual's load-bearing footprint which is defined as the upper
surface of the shoe sole that is in physical contact with and supports the
human
foot sole.
Fig. 4~B shows the same fully rounded design when upright. under
normal load (body weight) and therefore deformed naturally in a manner very
closely paralleling the natural deformation under the same load of the foot.
An
almost identical portion of the foot sole that is flattened in deformation is
also
c flattened in deformation in the shoe sole. Fig. 45C shows the same design
when
tilted outward 20 degrees laterally, the normal bare foot limit; with
virtually equal
accuracy it shows the opposite foot tilted 20 degrees inward, in fairly severe
pronation. As shown, the deformation of the rounded shoe sole 28 again very
closely parallels that of the foot, even as it tilts. Just as the area of foot
contact is
almost as great when tilted 20 degrees, the flattened area of the deformed
shoe
sole is also nearly the same as when upright. Consequently, the bare foot
fully
supported structurally and its natural stability is maintained undiminished,
regardless of shoe tilt. In marked contrast, a conventional shoe, shown in
Fig. 2,
makes contact with the ground with only its relatively sharp edge when tilted
and
2 o is therefore inherently unstable.
The capability to deform naturally is a design feature of the applicant's
naturally rounded shoe sole designs, whether fully rounded or rounded only at
the
sides, though the fully rounded design is most optimal and is the most
natural,
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general case, assuming shoe sole material such as to allow ~ natural
deformation. It
is an important feature because. by following the natural deformation of the
human foot, the naturally deforming shoe sole can avoid interfering with the
natural biomechanics of the foot and ankle.
Fig. 46C also represents with reasonable accuracy a shoe sole design
corresponding to Fig. 4~B, a naturally rounded shoe sole with a conventional
built-in flattening deformation, as in Fig. 14 above, except that design would
have
a slight crimp at 146. Seen in this light, the naturally rounded side design
in Fig.
4~B is a more conventional, conservative design that is a special case of the
more
_" Generally fully rounded design in Fig. 4~A, which is the closest to the
natural
form of the foot, but the least conventional. The natural deformation of the
applicant's shoe sole design follows that of the foot very closely so that
both
provide a nearly equal flattened base to stabilize the foot.
Fig. 46 shows the preferred relative density of the shoe sole, including the
15 insole as a part, in order to maximize the shoe sole's ability to deform
naturally
following the natural deformation of the foot sole. Regardless of how many
shoe
sole layers (including insole) or laminations of differing material densities
and
flexibility are used in total, the softest and most flexible material 147
should be
closest to the foot sole, with a progression through less soft 148, such as a
2 o midsole or heel lift, to the firmest and least flexible 149 at the
outermost shoe sole
layer, the bottom sole. This arrangement helps to avoid the unnatural side
lever
arm/torque problem mentioned in the previous several figures. That problem is
most severe when the shoe sole is relatively hard and non-deforming uniformly
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throughout the shoe sole, like most conventional street shoes. since hard
material
transmits the destabilizing torque most effectively by providing a rigid lever
arm.
The relative density shown in Fig. 46 also helps to allow the shoe sole to
duplicate the same kind of natural deformation exhibited by the bare foot sole
in
Fig. 43, since the shoe sole layers closest to the foot, and therefore with
the most
severe contours, have to deform the most in order to flatten like the barefoot
and
consequently need to be soft to do so easily. This shoe sole arrangement also
replicates roughly the natural bare foot, which is covered with a very tough
"Seri
boot" outer surface (protecting a softer cushioning interior of fat pads)
among
o primitive barefoot populations.
Finally, the use of natural relative density as indicated in this figure will
allow more anthropomorphic embodiments of the applicant's designs (right and
left sides of Fig. 46 show variations of different degrees) with sides going
higher
around the side contour of the foot and thereby blending more naturally with
the
~ s sides of the foot. These conforming sides will not be effective as
destabilizing
lever arms because the shoe sole material there would be soft and unresponsive
in
transmitting torque, since the lever arm will bend.
As a point of clarification, the forgoing principle of preferred relative
density refers to proximity to the foot and is not inconsistent with the term
20 "uniform density" used in conjunction with certain embodiments of
applicant's
invention. Uniform shoe sole density is preferred strictly in the sense of
preserving even and natural support to the foot like the ground provides, so
that a
neutral starting point can be established, against which so-called
improvements
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can be measured. The preferred uniform densit<- is in marked contrast to the
common practice in athletic shoes today, especially those beyond cheap or
"bare
bones" models, of increasing or decreasing the densit'- of the shoe sole,
particularly in the midsole, in various areas underneath the foot to provide
extra
support or special softness where "believed necessary. The same effect is also
created by areas either supported or unsupported by the tread pattern of the
bottom sole. The most common example of this practice is the use of denser
midsole material under the inside portion of the heel, to counteract excessive
pronation.
Fig. 47 illustrates that the applicant's naturally rounded shoe sole sides can
be made to provide a fit so close as to approximate a custom fit. By molding
each
mass-produced shoe size with sides that are bent in somewhat from the position
29 they would normally be in to conform to that standard size shoe last, the
shoe
soles so produced w -ill very gently hold the sides of each individual foot
exactly.
Since the shoe sole is designed as described in connection W th Fig. 46 to
deform
easily and naturally like that of the bare foot, it w111 deform easily to
provide this
designed-in custom fit. The greater the flexibility of the shoe sole sides,
the
greater the range of individual foot size variations can be custom fit by a
standard
size. This approach applies to the fully rounded design described here in Fig.
20 4~A and in Fig. 1~ above, which would be even more effective than the
naturally
rounded sides design shown in Fig. 47.
Besides providing a better fit, the intentional undersizing of the flexible
shoe sole sides of Figure 47 allows for a simplified design utilizing a
geometric
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approximation of the true actual contour of the human. This geometric
approximation is close enough to provide a virtual custom fit, when
compensated
for by the flexible undersizing from standard shoe lasts described above.
Fig. 48 illustrates a fully rounded design, but abbreviated along the sides
to only essential structural stability and propulsion shoe sole elements as
shown in
Fig. 11 G-L above combined with freely articulating structural elements under-
neath the foot. The unifying concept is that, on both the sides and underneath
the
main load bearing portions of the shoe sole, only the important structural
(i.e.
bone) elements of the foot should be supported by the shoe sole, if the
natural
flexibility of the foot is to be paralleled accurately in shoe sole
flexibility, so that
the shoe sole does not interfere with the foot's natural motion. In a sense,
the shoe
sole should be composed of the same main structural elements as the foot and
they should articulate with each other just as do the main joints of the foot.
Fig. 48E shows the horizontal plane bottom view of the right foot
s corresponding to the fully rounded design previously described, but
abbreviated
along the sides to only essential structural support and propulsion elements.
Shoe
sole material density can be increased in the unabbreviated essential elements
to
compensate for increased pressure loading there. The essential structural
support
elements are the base and lateral tuberosity of the calcaneus 9~, the heads of
the
2o metatarsals 96, and the base of the fifth metatarsal 97 (and the adjoining
cuboid in
some individuals). They must be supported both underneath and to the outside
edge of the foot for stability. The essential propulsion element is the head
of the
first distal phalange 98. Fig. 48 shows that the naturally rounded stability
sides
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need not be used except in the identified essential areas. Weight savings and
flexibility improvements can be made by omitting the non-essential stability
sides.
The design of the portion of the shoe sole directly underneath the foot
shown in Fig. 48 allows for unobstructed natural inversion/eversion motion of
the
calcaneus by providing maximum shoe sole flexibility particularly between the
base of the calcaneus 12~ (heel) and the metatarsal heads 126 (forefoot) along
an
axis 124. An unnatural torsion occurs about that axis if flexibility is
insufficient
so that a conventional shoe sole interferes with the inversion/eversion motion
by
restraining it. The object of the design is to allow the relatively more
mobile (in
inversion and eversion) calcaneus to articulate freely and independently from
the
relatively more fixed forefoot instead of the fixed or fused structure or lack
of
stable structure between the nvo in conventional designs. In a sense, freely
articulating joints are created in the shoe sole that parallel those of the
foot. The
design is to remove nearly all of the shoe sole material between the heel and
the
forefoot, except under one of the previously described essential structural
support
elements, the base of the fifth metatarsal 97. An optional support for the
main
longitudinal arch 121 may also be retained for runners with substantial foot
pronation, although it would not be necessary for many runners.
2~ The forefoot can be subdivided (not shown) into its component essential
structural support and propulsion elements, the individual heads of the
metatarsal
and the heads of the distal phalanges, so that each major articulating joint
set of
the foot is paralleled by a freely articulating shoe sole support propulsion
element,
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an anthropomorphic design; various aggregations of the subdivision are also
possible.
The design in Fig. 48 features an enlarged structural support at the base of
the fifth metatarsal in order to include the cuboid, which can also come into
contact with the ground under arch compression in some individuals. In
addition,
the design can provide general side support in the heel area. as in Fig. 48E
or
alternatively can carefully orient the stabilitr~ sides in the heel area to
the exact
positions of the lateral calcaneal tuberosity 108 and the main base of the
calcaneus 109, as in Fig. 48E' (showing heel area only of the right foot).
Figs.
0 48A-48D show, frontal plane cross sections of the left shoe and Fig. 48E
shows a
bottom view of the right foot, with flexibiliy ayes 122, 124, 111, 112 and 113
indicated. Fig. 48F shows a sagittal plane cross section showing the
structural
elements joined by a very thin and relatively soft upper midsole layer. Figs.
48G
and 48H show similar cross sections with slightly different designs featuring
durable fabric only (slip-lasted shoe), or a structurally sound arch design,
respec-
tively. Fig. 48I shows a side medial view of the shoe sole.
Fig. 48J shows a simple interim or low cost construction for the
articulating shoe sole support element 9~ for the heel (showing the heel area
only
of the right foot): while it is most critical and effective for the heel
support
2 o element 9~, it can also be used with the other elements, such as the base
of the
fifth metatarsal 97 and the long arch 121. The heel sole element 9~ shown can
be
a single flexible layer or a lamination of layers. When cut from a flat sheet
or
molded in the general pattern shown, the outer edges can be easily bent to
follow
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the contours of the foot, particularly the sides. The shape shown allows a
flat or
slightly rounded heel element 9~ to be attached to a highly rounded shoe upper
or
ver<° thin upper sole layer like that shown in Fig. 48F. Thus, a very
simple
construction technique can yield a highly sophisticated shoe sole design. The
size
of the center section 119 can be small to conform to a fully or nearly fully
rounded design or larger to conform to a rounded sides design, where there is
a
large flattened sole area under the heel. The flexibility is provided by the
removed diagonal sections, the exact proportion of size and shape can vary.
Fig. 49 shows use of the theoretically ideal stability plane concept to
provide natural stability in negative heel shoe soles that are less thick in
the heel
area than in the rest of the shoe sole; specifically, a negative heel version
of the
naturally rounded sides conforming to a load-bearing foot design shown in Fig.
14 above.
Figs. 49A, 49B, and 49C represent frontal plane cross sections taken
s along the forefoot, at the base of the fifrh metatarsal, and at the heel,
thus
illustrating that the shoe sole thickness is constant at each frontal plane
cross
section, even though that thickness varies from front to back, due to the
sagittal
plane variation 40 (shown hatched) causing a lower heel than forefoot, and
that
the thickness of the naturally rounded sides is equal to the shoe sole
thickness in
2 o each Fig. 49A-49C cross-section. Moreover. in Fig. 49D, a horizontal plane
overview or top view of the left foot sole, it can be seen that the horizontal
contour of the sole follows the preferred principle in matching, as nearly as
practical, the rough footprint of the load-bearing foot sole.
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The abbreviation of essential structural support elements can also be
applied to negative heel shoe soles such as that shown in Fig. 49 and
dramatically
improves their flexibility. i\legative heel shoe soles such as Fig. 49 can
also be
modified by inclusion of aspects of the other embodiments disclosed herein.
Fig. ~0 shows, in Figs. BOA-SOD, possible sagittal plane shoe sole
thickness variations for negative heel shoes. The hatched areas indicate the
forefoot lift or wedge 40. At each point along the shoe soles seen in sagittal
plane
cross sections, the thickness varies as shown in Figs. BOA-SOD, while the
thickness of the naturally rounded sides 28a, as measured in the frontal
plane,
equal and therefore vary directly with those sagittal plane thickness
variations.
Fig. BOA shows the same embodiment as Fig. 49.
Fig. S 1 shows the application of the theoretically ideal stability plane
concept in flat shoe soles that have no heel lift to provide for natural
stability,
maintaining the same thickness throughout, with rounded stability sides
abbreviated to only essential structural support elements to provide the shoe
sole
with natural flexibility paralleling that of the human foot.
Figs. S lA, S 1B, and 51 C represent frontal plane cross-sections taken
along the forefoot, at the base of the fifth metatarsal, and at the heel, thus
illustrating that the shoe sole thickness is constant at each frontal plane
cross
2 o section, while constant in the sagittal plane from front to back, so that
the heel
and forefoot have the same shoe sole thickness, and that the thickness of the
naturally rounded sides is equal to the shoe sole thickness in each Fig. 51 A-
51 C
cross-section. Moreover, in Fig. ~ 1 C, a horizontal plane overview or top
view of
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the left foot sole, it can be seen that the horizontal contour of the sole
follows the
preferred principle in matching, as nearly as practical. the rough footprint
of the
load-bearing foot sole. Fig. ~ 1 E, a sagittal plane cross section, shows that
shoe
sole thickness is constant in that plane.
Fig. ~ 1 shows the applicant's prior invention of contour sides abbreviated
to essential structural elements, as applied to a flat shoe sole. Fig. ~ 1
shows the
horizontal plane top view of fully rounded shoe sole of the left foot
abbreviated
along the sides to only essential structural support and propulsion elements
(shown hatched). Shoe sole material density can be increased in the
unabbreviated essential elements to compensate for increased pressure loading
there. The essential structural support elements are the base and lateral
tuberosity
of the calcaneus 9~, the heads of the metatarsals 96, and base of the fifth
metatarsal 97. They must be supported both underneath and to the outside for
stability. The essential propulsion element is the head of the first distal
phalange
~ 5 98.
The medial (inside) and lateral (outside) sides supporting the base and
lateral tuberosiiy of the calcaneus are shown in Fig. ~ 1 oriented in a
conventional
way along the longitudinal axis of the shoe sole, in order to provide direct
structural support to the base and lateral tuberosity of the calcaneus, but
can be
20 located also along either side of the horizontal plane subtalar ankle joint
axis .
Fig. ~ 1 shows that the naturally rounded stability sides need not be used
except in
the identified essential areas. Weight savings and flexibility improvements
can be
made by omitting the non-essential stability sides. A horizontal plane bottom
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view (not show n) of Fig. ~ 1 would be the e:cact reciprocal or converse of
Fig. ~ 1
with the peaks and valleys contours exactly reversed.
Flat shoe soles such as Fig. ~ 1 can also be modified by inclusion of
various aspects of the other embodiments disclosed herein.
Central midsole section 188 and upper section 187 in Fig. 12 must fulfill a
cushioning function which frequently calls for relatively soft midsole
material.
The shoe sole thickness effectively decreases in the Fig. 12 embodiment when
the
soft central section is deformed under weight-bearing pressure to a greater
extent
than the relatively firmer sides.
i o In order to control this effect, it is necessary to measure it. What is
required is a methodology of measuring a portion of a static shoe sole at rest
that
will indicate the resultant thickness under deformation. A simple approach is
to
take the actual least distance thickness at any point and multiply it times a
factor
for deformation or "give", which is typically measured in durometers (on Shore
A
~ 5 scale), to get a resulting thickness under a standard deformation load.
Assuming
a linear relationship (which can be adjusted empirically in practice), this
method
would mean that a shoe sole midsection of 1 inch thickness and a fairly soft
30
durometer would be roughly functionally equivalent under equivalent load-
bearing deformation to a shoe midsole section of 1/2 inch and a relatively
hard 60
2o durometer; they would both equal a factor of 30 inch-durometers. The exact
methodology can be changed or improved empirically, but the basic point is
that
static shoe sole thickness needs to have a dynamic equivalent under equivalent
loads, depending on the density of the shoe sole material.
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Since the Theoretically Ideal Stability Plane ~ 1 has already been generally
defined in part as having a constant frontal plane thickness and preferring a
uniform material density to avoid arbitrarily altering natural foot motion, it
is
logical to develop a non-static definition that includes compensation for shoe
sole
material density. The Theoretically Ideal Stability Plane defined in dynamic
terms would alter constant thickness to a constant multiplication product of
thickness times density.
Using this restated definition of the Theoretically Ideal Stability Plane
presents an interesting design possibility: the somewhat extended width of
shoe
o sole sides that are required under the static definition of the
Theoretically Ideal
Stability Plane could be reduced by using a higher density midsole material in
the
naturally rounded sides.
Fig. ~2 shows, in frontal plane cross section at the heel, the use of a high
density (d') midsole material on the naturally rounded sides and a low density
(d)
midsole material everywhere else to reduce side width. To illustrate the
principle,
it was assumed in Fig. ~2 that density (d') is twice that of density (d), so
the effect
is somewhat exaggerated, but the basic point is that shoe sole width can be
reduced si~ificantly by using the Theoretically Ideal Stability Plane with a
definition of thickness that compensates for dynamic force loads. In the Fig.
52
2 o example, about one fourth of an inch in width on each side is saved under
the
revised definition, for a total width reduction of one half inch, while rough
functional equivalency should be maintained, as if the frontal plane thickness
and
density were each unchanging.
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As shown in Fig. ~2. the boundaw between sections of different density is
indicated by the line 4~ and the line ~ 1' parallel to ~ 1 at half the
distance from the
outer surface of the foot 29.
Note that the design in Fig. 52 uses low densiy midsole material, which is
effective for cushioning, throughout that portion of the shoe sole that
~.~ould be
directly load-bearing from roughly 10 degrees of inversion to roughly 10
degrees
eversion, the normal range of maximum motion during athletics; the higher
density midsole material is tapered in from roughly 10 degrees to 30 degrees
on
both sides, at which ranges cushioning is less critical than providing
stabilizing
support.
Fig. ~3 show the footprints of the natural barefoot sole and shoe sole. The
footprints are the areas of contact between the bottom of the foot or shoe
sole and
the flat, horizontal plane of the ground, under normal body weight-bearing
conditions. Fig. ~3A shows a typical right footprint outline 37 when the foot
is
is upright with its sole flat on the ground.
Fig. 53B shows the footprint outline 17 of the same foot when tilted out
20 degrees to about its normal limit; this footprint corresponds to the
position of
the foot shown in Fig. 43 above. Critical to the inherent natural stability of
the
barefoot is that the area of contact between the heel and the ground is
virtually
2 o unchanged, and the area under the base of the fifth metatarsal and cuboid
is
narrowed only slightly. Consequently, the barefoot maintains a wide base of
support even when tilted to its most extreme lateral position.
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The major difference shown in Fig. ~3B is clearly in the forefoot. where
all of the heads of the first through fourth metatarsals and their
corresponding
phalanges no longer make contact with the ground. Of the forefoot. only the
head
of the fifth metatarsal continues to make contact with the ground, as does its
corresponding phalange, although the phalange does so only slightly. The
forefoot
motion of the forefoot is relatively great compared to that of the heel.
Fig. 53C shows a shoe sole print outline of a shoe sole of the same size as
the bare foot in Figs. ~3A & ~3B when tilted out 20 degrees to the same
position
as Fig ~3B; this position of the shoe sole corresponds to that shown in Fig.
4=1
above. The shoe sole maintains only a very narrow bottom edge in contact with
the ground, an area of contact many times less than the bare foot.
Fig. ~4 shows two footprints like footprint 37 in Fig. ~3A of a bare foot
upright and footprint 17 in Fig. ~3B of a bare foot tilted out 20 degrees, but
showing also their actual relative positions to each other as the foot rolls
outward
from upright to tilted out 20 degrees. The bare foot tilted footprint is shown
hatched. The position of tilted footprint 17 so far to the outside of upright
footprint 37 demonstrates the requirement for greater shoe sole width on the
lateral side of the shoe to keep the foot from simply rolling off of the shoe
sole;
this problem is in addition to the inherent problem caused by the rigidiy of
the
2 c conventional shoe sole. The footprints are of a high arched foot.
Fig. ~~ shows the applicant's invention of shoe sole with a lateral stability
sipe 11 in the form of a vertical slit. The lateral stability sipe allows the
shoe sole
to flex in a manner that parallels the foot sole, as seen is Figs. ~3 & ~4.
The lateral
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stability ripe 11 allows the forefoot of the shoe sole to pivot off the around
with
the wear's forefoot when the wearer's foot rolls out laterally. At the same
time, it
allows the remaining shoe sole to remain flat on the around under the wearer's
load-bearing tilted footprint 17 in order to provide a firm and natural base
of
.. structural support to the wearer's heel, his fifth metatarsal base and
head, as well
as cuboid and fifth phalange and associated softer tissues. In this way, the
lateral
stabiliy sipe provides the wearer of even a conventional shoe sole with
lateral
stability like that of the bare foot. All types of shoes can be distinctly
improved
with this invention, even women s high heeled shoes.
With the lateral stability sipe, the natural supination of the foot, which is
its ourivard rotation during load-bearing, can occur with greatly reduced
obstruction. The functional effect is analogous to providing a car with
independent suspension, with the axis aligned correctly. At the same time, the
principle load-bearing structures of the foot are firmly supported with no
sipes
directly underneath.
Fig. ~~A is a top view of a conventional shoe sole with a corresponding
outline of the wearer's footprint superimposed on it to identify the position
of the
lateral stability sipe 11, which is fixed relative to the wearer's foot, since
it
removes the obstruction to the foot' s natural lateral flexibility caused by
the
2 o conventional shoe sole.
With the lateral stability sipe 11 in the form of a vertical slit, when the
foot sole is upright and flat, the shoe sole provides firm structural support
as if the
sipe were not there. No rotation beyond the flat position is possible with a
sipe in
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the form of a slit, since the shoe sole on each side of the slit prevents
further
motion.
Many variations of the lateral stabiliy sipe 11 are possible to provide the
same unique functional goal of providing shoe sole flexibiliy along the
general
axis shoves in Fig. 5~. For example, the slit can be of various depths
depending
on the flexibility of the shoe sole material used; the depth can be entirely
through
the shoe sole, so long as some flexible material acts as a joining hinge, like
the
cloth of a fully lasted shoe, which covers the bottom of the foot sole, as
well as
the sides. The slits can be multiple, in parallel or aske«~. They can be
offset from
_" vertical. They can be straight lines, jagged lines, curved lines or
discontinuous
lines.
Although slits are preferred, other sipe forms such as channels or
variations in material densities as described above can also be used, though
many
such forms will allow varying degrees of further pronation rotation beyond the
flat position, which may not be desirable, at least for some categories of
runners.
Other methods in the existing art can be used to provide flexibility in the
shoe
sole similar to that provided by the lateral stability sipe along the axis
shown in
Fig. ~~.
The axis shown in Fia. ~~ can also vary somewhat in the horizontal plane.
2o For example, the footprint outline 37 shown in Fig. ~~ is positioned to
support the
heel of a high arched foot; for a low arched foot tending toward excessive
pronation, the medial origin 14 of the lateral stability sipe would be moved
forward to accommodate the more inward or medial position of pronator's heel.
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The axis position can also be varied for a corrective purpose tailored to the
individual or category of individual: the a<~cis can be moved toward the heel
of a
rigid, high arched foot to facilitate pronation and flexibiliy, and the axis
can be
moved away from the heel of a flexible, low arched foot to increase support
and
reduce pronation.
It should be noted that various forms of firm heel counters and motion
control devices in common use can interfere with the use of the lateral
stability
sipe by obstructing motion along its axis; therefore, the use of such heel
counters
and motion control devices should be avoided. The lateral stability ripe may
also
_" compensate for shoe heel-induced ourivard knee cant.
Fig. ~~B is a cross section of the shoe sole 22 writh lateral stability- sipe
11.
The shoe sole thickness is constant but could van as do many conventional and
unconventional shoe soles known to the art. The shoe sole could be
conventionally flat like the ground or conform to the shape of the wearer's
foot.
Fig. ~~C is a top view like Fig. »A, but showing the print of the shoe
sole with a lateral stability sipe when the shoe sole is tilted outward 20
degrees, so
that the forefoot of the shoe sole is not longer in contact with the ground,
while
the heel and the lateral section do remain flat on the ground.
Fig. ~6 shows a conventional shoe sole with a medial stability sipe 12 that
2 o is like the lateral sipe 11. but with a purpose of providing increased
medial or
pronation stability instead of lateral stability; the head of the first
metatarsal and
the first phalange are included with the heel to form a medial support section
inside of a flexibility axis defined by the medial stability sipe 12. The
medial
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stabiliy sipe 1? can be used alone. as shown, or together with the lateral
stabiliy
sipe 11, which is not shown.
Fig. 57 shows footprints 37 and 17, like Fig. 54, of a right barefoot
upright and tilted out 20 degrees, showing the actual relative positions to
each
other as a low arched foot rolls outward from upright to tilted out 20
degrees. The
low arched foot is particularly noteworthy because it exhibits a wider range
of
motion than the Fig. 54 high arched foot, so the 20 degree lateral tilt
footprint 17
is farther to the outside of upright footprint 37. In addition. the low arched
foot
pronates inward to inner footprint borders 18; the hatched area 19 is the
increased
area of the footprint due to the pronation, whereas the hatched area 16 is the
decreased area due to pronation.
In Fig. 57, the lateral stability sipe 11 is clearly located on the shoe sole
along the inner margin of the lateral footprint 17 superimposed on top of the
shoe
sole and is straight to maximize ease of flexibilit<~. The basic Fig. 57
design can
of course also be used without the lateral stability sipe 11.
A shoe sole of extreme width is necessitated by the common foot
tendency toward excessive pronation, as shown in Fig. 57, in order to provide
structural support for the full range of natural foot motion, including both
pronation and supination. Extremely wide shoe soles are most practical if the
2 ~ sides of the shoe sole are not flat as is conventional but rather are bent
up to
conform to the natural shape of the shoe wearer's foot sole.
Figures 58A-58D shows the use of flexible and relatively inelastic fiber in
the form of strands, woven or unwoven (such as pressed sheets), embedded in
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midsole and bottom sole material. Optimally, the fiber strands parallel (at
least
roughly) the plane surface of the wearer's foot sole in the nattnally rounded
design
in Figs. 58A-58C and parallel the flat ground in Fig. 58D, which shows a
section
of conventional, non-rounded shoe sole. Fiber orientations at an angle to this
parallel position will still provide improvement over conventional soles
without
fiber reinforcement, particularly if the angle is relatively small; however,
very
large angles or omni-directionality of the fibers will result in increased
rigidity or
increased softness.
This preferred orientation of the fiber strands, parallel to the plane of the
wearer's foot sole, allows for the shoe sole to deform to flatten in parallel
with the
natural flattening of the foot sole under pressure. At the same time, the
tensile
strength of the fibers resist the downward pressure of body weight that would
normally squeeze the shoe sole material to the sides. so that the side walls
of the
shoe sole will not bulge out (or will do so less so). The result is a shoe
sole
material that is both flexible and firm. This unique combination of functional
traits is in marked contrast to conventional shoe sole materials in which
increased
flexibility unavoidably causes increased softness and increased firmness also
increases rigidity. Fig. 58A is a modification of Fig. 5A, Fig. 58B is Fig. 6
modified and Fig. 58C is Fig. 7 modified. The position of the fibers shown
would
2 o be the same even if the shoe sole material is made of one uniform material
or of
other layers than those shown here.
The use of the fiber strands, particularly when woven, provides protection
against penetration by sharp objects, much like the fiber in radial automobile
tires.
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The fiber can be of my size, either individually or in combination to form
strands;
and of any material W th the properties of relative inelasticiy (to resist
tension
forces) and flexibility. The strands of fiber can be short or long. continuous
or
discontinuous. The fibers facilitate the capability of any shoe sole using
them to
be flexible but hard under pressure, like the foot sole.
It should also be noted that the fibers used in both the cover of insoles and
the Dellinger Web is knit or loosely braided rather than woven, which is not
preferred, since such fiber strands are designed to stretch under tensile
pressure so
that their ability to resist sideways deformation would be greatly reduced
compared to non-knit fiber strands that are individually (or in t<visted
groups of
yarn) woven or pressed into sheets.
Figures 59A-~9D are Figs. 9A-D modified to show the use of flexible
inelastic fiber or fiber strands, woven or uwvoven (such as pressed) to make
an
embedded capsule shell that surrounds the cushioning compartment 161
containing a pressure-transmitting medium like gas, gel, or liquid. The
fibrous
capsule shell could also directly envelope the surface of the cushioning
compartment, which is easier to construct, especially during assembly. Fig.
~9E
is a figure showing a fibrous capsule shell 191 that directly envelopes the
surface
of a cushioning compartment 161; the shoe sole structure is not fully rounded,
2 o like Fig. 59A, but naturally rounded, and has a flat middle portion
corresponding
to the flattened portion of a wearer's load-bearing foot sole.
Figure ~9F shows a unique combination of the Figs. 9 & 10 design above.
The upper surface 16~ and lower surface 166 contain the cushioning
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compartment 161, which is subdivided into tv,-o parts. The lower half of the
cushioning compartment 161 is both structured and functions like the compart-
ment sho~in in Fig. 9 above. The upper half is similar to Fig. 10 above but
subdivided into chambers 192 that are more geometrically regular so that
construction is simpler; the structure of the chambers 192 can be of
honeycombed
in structure. The advantage of this design is that it copies more closely than
the
Fig. 9 desi~ the actual structure of the wearer's foot sole, while being much
more
simple to construct than the Fig. 10 design. Like the wearer's foot sole, the
Fig.
~9F design would be relative soft and flexible in the lower half of the
chamber
161, but firmer and more protective in the upper half, where the mini-chambers
192 would stiffen quickly under load-bearing pressure. Other mufti-level
arrangements are also possible.
Figures 60A-60D show the use of embedded flexible inelastic fiber or
fiber strands, woven or unwoven, in various embodiments similar those shown in
Figs. ~8A-~8D. Fig. 60E is a figure showing a frontal plane cross section of a
fibrous capsule shell 191 that directly envelopes the surface of the midsole
section
188.
Figure 61C compares the footprint made by a conventional shoe 3~ writh
the relative positions of the wearer's right foot sole in the maximum
supination
2 o position 37a and the maximum pronation position 37b. Figure 61 C
reinforces the
indication that more relative sideways motion occurs in the forefoot and
midtarsal
areas, than in the heel area.
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<~s shown in Fig. 61 C. at the extreme limit of supination and pronation
foot motion, the base of the calcaneus 109 and the lateral calcaneal
tuberositv 108
roll slightly off the sides of the shoe sole outer boundary 3~. However, at
the
same extreme limit of supination, the base of the fifth metatarsal 97 and the
head
of the fifth metatarsal 94 and the fifth distal phalange 93 all have rolled
completely off the outer boundary 3~ of the shoe sole.
Figure 61D shows an overhead perspective of the actual bone structures of
the foot.
Figure 62 is similar to Fig. ~7 above, in that it shows a shoe sole that
covers the full range of motion of the wearer's right foot sole, with or
without a
sipe 11. However, while covering that full range of motion, it is possible to
abbreviate the rounded sides of the shoe sole to only the essential structural
and
propulsion elements of the foot sole, as previously discussed herein.
Figure 63 shows an electronic image of the relative forces present at the
1 J different areas of the bare foot sole when at the maximum supination
position
shown as 37a in Figure 62 above; the forces were measured during a standing
simulation of the most common ankle spraining position. The maximum force
was focused at the head of the fifth metatarsal and the second highest force
was
focused at the base of the fifth metatarsal. Forces in the heel area were
2 o substantially less overall and less focused at any specific point.
Fig. 63 indicates that, among the essential structural support and
propulsion elements shown in Figure 40 above, there are relative degrees of
importance. In terms of preventing ankle sprains, the most common athletic
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injuy (about two-thirds occur in the extreme supination position 37a shown in
Fig. 62), Fig. 63 indicates that the head of the fifth metatarsal 94 is the
most
critical single area that must be supported by a shoe sole in order to
maintain
barefoot-like lateral stability. Fig. 63 indicates that the base of the fifth
metatarsal
., 97 is very close to being as important. Generally, the base and the head of
the
fifth metatarsal are completely unsupported by a conventional shoe sole.
Figs. 64A-6=1B demonstrate a variation in the theoretically ideal stability
plane. In previously described embodiments, the inner surface of the
theoretically
ideal stability plane conforms to the shape of the wearer's foot, especially
its
sides, so that the inner surface of the applicant's shoe sole invention
conforms to
the outer surface of the wearer's foot sole, especially it sides, when
measured in
frontal plane or transverse plane cross sections. For illustration purposes,
the
right side of Fig. 64 explicitly illustrates such an embodiment.
The right side of Fig. 64 includes an upper shoe sole surface that is
1 ~ complementary to the shape of all or a portion the w-earer's foot sole. In
addition,
this application describes shoe rounded sole side designs wherein the inner
surface of the theoretically ideal stability plane lies at some point
bet~.veen
conforming or complementary to the shape of the wearer's foot sole, that is --
roughly paralleling the foot sole including its side -- and paralleling the
flat
2c ground; that inner surface of the theoretically ideal stability plane
becomes load-
bearing in contact with the foot sole during foot inversion and eversion,
which is
normal sideways or lateral motion.
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.~~ain, for illustration purposes. the left side of Fig. 6=1B describes shoe
sole side designs wherein the lower surface of the theoretically ideal
stabilit~~
plane, which equates to the load-bearing surface of the bottom or outer shoe
sole,
of the shoe sole side portions is above the plane of the underneath portion of
the
shoe sole, when measured in frontal or transverse plane cross sections; that
lower
surface of the theoretically ideal stability plane becomes load-bearing in
contact
w-zth the ground during foot inversion and eversion, which is normal sideways
or
lateral motion.
Although the inventions described in this application may in some
1 a instances be less than optimal, they nonetheless distinguish over all
prior art and
still do provide a significant stability improvement over existing footwear
and
thus provide significantly increased injury prevention benefit compared to
existing footwear.
Fig. 6~ provides a means to measure the rounded shoe sole sides incorpo-
15 rated in the applicant's inventions described above. Fig. 6~ correlates the
height
or extent of the rounded side portions of the shoe sole with a precise angular
measurement from zero to 180 degrees. That angular measurement corresponds
roughly with the support for sideways tilting provided by the rounded shoe
sole
sides of any angular amount from zero degrees to 180 degrees, at least for
such
2 o rounded sides proximate to any one or more or all of the essential
stability or
propulsion structures of the foot, as defined above. The rounded shoe sole
sides
as described in this application can have any angular measurement from zero
degrees to 180 degrees.
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Figs. 66A-66F, Fig.67A-67E and Fig. 68 describe shoe sole structural
inventions that are formed with an upper surface to conform, or at least be
complementary, to the all or most or at least part of the shape of the
wearer's foot
sole, whether under a body weight load or unloaded, but without rounded
stabilin~
sides as defined by the applicant. As such, Figs. 66-68 are similar to Figs.
38-40
above. but without the rounded stability sides at the essential structural
support
and propulsion elements, which are the base and lateral tuberosity of the
calcaneus, the heads of the first and fifth metatarsals, the base of the fifth
metatarsal, and the first distal phalange, and with shoe sole rounded side
thickness variations, as measured in frontal plane cross sections as defined
in this
and earlier applications.
Figs. 66A-66F, Fig. 67A-67E, and Fig. 68, like the many other variations
of the applicant's naturally rounded design described in this application,
show a
shoe sole invention wherein both the upper, foot sole-contacting surface of
the
_., shoe sole and the bottom, ground-contacting surface of the shoe sole
mirror the
contours of the bottom surface of the wearer's foot sole, forming in effect a
flexible three dimensional mirror of the load-bearing portions of that foot
sole
when bare.
The shoe sole shown in Figs. 66-68 preferably include an insole layer, a
z;; midsole layer, and bottom sole layer, and variation in the thickness of
the shoe
sole, as measured in sagittal plane cross sections, like the heel lift common
to
most shoes, as well as a shoe upper.
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Figure 69A-69D shows the implications of relative difference in range of
motions between forefoot. midtarsal, and heel areas. FiQ. 69A-D is a modifica-
tion of Fig. 33 above, with the left side of the figures showing the required
range
of motion for each area.
Fig. 69A shows a cross section of the forefoot area and therefore on the
left side shows the highest rounded sides (compared to the thickness of the
shoe
sole in the forefoot area) to accommodate the greater forefoot range of
motion.
The rounded side is sufficiently high to support the entire range of motion of
the
wearer's foot sole. Note that the sock liner or insole ? is shown.
1 o Fig. 69B shows a cross section of the midtarsal area at about the base of
the fifth metatarsal, which has somewhat less range of motion and therefore
the
rounded sides are not as high (compared to the thickness of the shoe sole at
the
midtarsal area). Fig. 69C shows a cross section of the heel area, where the
range
of motion is the least, so the height of the rounded sides is relatively least
of the
three general areas (when compared to the thickness of the shoe sole in the
heel
area).
Each of the three general areas, forefoot, midtarsal and heel, have rounded
sides that differ relative to the high of those sides compared to the
thiclmess of the
shoe sole in the same area. At the same time, note that the absolute height of
the
2 o rounded sides is about the same for all three areas and the contours have
a similar
outward appearance, even though the actual structure differences are quite
significant as shown in cross section.
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In addition, the rounded sides shown in Fig. 69A-D can be abbreviated to
support only those essential structural support and propulsion elements
identified
in Fig. 40 above. The essential structural support elements are the base and
lateral tuberosity of the calcaneus 9~, the heads of the metatarsals 96. and
the base
of the fifth metatarsal 97. The essential propulsion element is the head of
the
first distal phalange 98.
Figure 70 shows a similar view of a bottom sole structure 149, but with no
side sections. The areas under the forefoot 126. heel 12~, and base of the
fifth
metatarsal 97 would not be glued or attached firmly, while the other area (or
most
of it) would be glued or firmly attached. FiQ. 70 also shows a modification of
the
outer periphery of the convention shoe sole 36: the typical indentation at the
base
of the fifth metatarsal is removed, replaced by a fairly straight line 100.
Figure 71 shows a similar structure to Fig. 70, but with only the section
under the forefoot 126 unglued or not firmly attached; the rest of the bottom
sole
149 (or most of it) would be Glued or firmly attached.
Figures 72G-72H show shoe soles with only one or more, but not all, of
the essential stability elements (the use of all of which is still preferred)
but
which, based on Fig. 63, still represent major stability improvements over
existing footwear. This approach of abbreviating structural support to a few
2 o elements has the economic advantage of being capable of construction using
conventional flat sheets of shoe sole material, since the individual elements
can
be bent up to the contour of the wearer's foot with reasonable accuracy and
without difficulty. Whereas a continuous naturally rounded side that extends
all
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o~ or even a significant portion of, the way around the w -earer's foot sole
would
buckle partially since a flat surface cannot be accurately fitted to a rounded
surface; hence, injection molding is required for accuracy.
The features of Figs. 72G-72H can be used in combination with the
designs shown in this application. Further, various combinations of
abbreviated
structural support elements may be utilized other than those specifically
illustrated in the figures.
Figure 72G shows a shoe sole combining the additional stability
corrections 96a, 96b, and 98a supporting the first and fifth metatarsal heads
and
distal phalange heads. The dashed line 98a' represents a symmetrical optional
stability addition on the lateral side for the heads of the second through
fifth distal
phalanges, which are less important for stability.
Figure 72H shows a shoe sole with symmetrical stability additions 96a
and 96b. Besides being a major improvement in stability over existing
footwear,
15 this design is aesthetically pleasing and could even be used with high heel
type
shoes, especially those for women, but also any other form of footwear where
there is a desire to retain relatively conventional looks or where die shear
height
of the heel or heel lift precludes stability side corrections at the heel or
the base of
the fifth metatarsal because of the required extreme thickness of the sides.
This
2 c approach can also be used where it is desirable to leave the heel area
conventional, since providing both firmness and flexibility in the heel is
more
difficult that in other areas of the shoe sole since the shoe sole thickness
is usually
much greater there; consequently, it is easier, less expensive in terms of
change,
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and less of a risk in departing from well understood prior art just to provide
additional stability corrections to the forefoot and/or base of the fifth
metatarsal
area only.
Since the shoe sole thickness of the forefoot can be kept relatively thin,
., even with very high heels, the additional stability corrections can be kept
relatively inconspicuous. They can even be extended beyond the load-bearing
range of motion of the wearer's foot sole, even to wrap all the way around the
upper portion of the foot in a strictly ornamental way (although they can also
play
a part in the shoe upper's structure), as a modification of the strap, for
example,
1 c often seen on conventional loafers.
Figs. 73A-73D show close-up cross sections of shoe soles modified with
the applicant's inventions for deformation sipes.
Fig. 73A shows a cross section of a design with deformation sipes in the
form of channels, but with most of the channels filled with a material 170
flexible
s enough that it still allows the shoe sole to deform like the human foot.
Fig. 73B
shows a similar cross section with the channel sipes extending completely
through the shoe sole, but with the intervening spaces also filled with a
flexible
material 170 like Fig 73A; a flexible connecting top layer 123 can also be
used,
but is not shown. The relative size and shape of the sipes can vary almost
2 o infinitely. The relative proportion of flexible material 170 can vary,
filling all or
nearly all of the sipes, or only a small portion, and can vary between sipes
in a
consistent or even random pattern. As before, the exact structure of the sipes
and
filler material 170 can vary widely and still provide the same benefit, though
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some variations will be more effective than others. Besides the flexible
connecting utility of the filler material 170, it also ser<~es to keep out
pebbles and
other debris that can be caught in the sipes, allowing relatively normal
bottom
sole tread patterns to be created.
Fig. 73C shows a similar cross section of a design with deformation sipes
in the form of channels that penetrate the shoe sole completely and are
connected
by a flexible material 170 which does not reach the upper surface 30 of the
rounded shoe sole 28. Such an approach creates can create and upper shoe sole
surface similar to that of the trademarked Maseur sandals. but one where the
o relative positions of the various sections of the upper surface of the shoe
sole will
vary between each other as the shoe sole bends up or down to conform to the
natural deformation of the foot. The shape of the channels should be such that
the
resultant shape of the shoe sole sections would be similar but rounded: in
fact,
like the Maseur sandals. cylindrical with a rounded or beveled upper surface
is
S probably optimal. The relative position of the flexible connecting material
170
can vary widely and still provide the essential benefit. Preferably, the
attachment
of the shoe uppers would be to the upper surface of the flexible connecting
material 170.
A benefit of the Fig. 73C design is that the resulting upper surface 30 of
2 c the shoe sole can change relative to the surface of the foot sole due to
natural
deformation during normal foot motion. The relative motion makes practical the
direct contact between shoe sole and foot sole without intervening insoles or
socks, even in an athletic shoe. This constant motion between the two surfaces
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allows the upper surface of the shoe sole to be roughened to stimulate the
development of tough calluses (called a "Seri boot"). as described at the end
of
FiQ. 10 above, without creating points of irritation from constant, unrelieved
rubbing of exactly the same corresponding shoe sole and foot sole points of
.. contact.
Fig. 73C shows a similar cross section of a design with deformation sipes
in the form of angled channels in roughly and inverted V shape. Such a
structure
allows deformation bending freely both up and down; in contrast deformation
slits can only be bent up and channels with parallel side walls 1 ~ 1
generally offer
- . only a limited range of downward motion. The Fig. 73D angled channels
would
be particularly useful in the forefoot area to allow the shoe sole to conform
to the
natural contour of the toes, which curl up and then down. As before. the exact
structure of the angle channels can vary widely and still provide the same
benefit,
though some variations will be more effective than others. Finally, though not
shown. deformation slits can be aligned above deformation channels, in a sense
continuing the channel in circumscribed form.
Figure 74 shows sagittal plane shoe sole thickness variations, such as heel
lifts 38 and forefoot lifts 40, and how the rounded sides 28a equal and
therefore
vary with those varying thicknesses, as discussed in connection with Figure
31.
Fig. 7~ shows, in Figs. 7~A-7~C, a method, known from the prior art, for
assembling the midsole shoe sole structure of the present invention, showing
in
Figure 75C the general concept of inserting the removable midsole insert 14~
into
the shoe upper and sole combination in the same very simple manner as an
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intended wearer inserts his foot into the shoe upper and sole combination.
Figures 7~A and 7~B show a similar insertion method for the bottom sole 149.
The combinations of the many elements the applicant's invention
introduced in the preceding figures are shown because those embodiments are
considered to be at least among the most useful. However, many other useful
combinations embodiments are also clearly possible. but cannot be shown simply
because of the impossibility of showing them all while maintaining a
reasonable
brevity and conciseness in what is already an unavoidably long description due
to
the inherently highly interconnected nature of the inventions shown herein,
each
1 a of which can operate independently or as part of a combination of others.
Therefore, any combination that is not explicitly described above is
implicit in the overall invention of this application and, consequently, any
part of
any of the preceding Figures 1-7~ and/or textual specification can be combined
with any other part of any one or more other of the Figures 1-7~ and/or
textual
i s specification of this application to make new and useful improvements over
the
existing art.
In addition, any unique new part of any of the preceding Figures 1-75
and/or associated textual specification can be considered by itself alone as
an
individual improvement over the existing art.
2 o The foregoing shoe designs meet the objectives of this invention as stated
above. However, it will clearly be understood by those skilled in the art that
the
foregoing description has been made in terms of the preferred embodiments and
various changes and modifications may be made without departing from the
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scope of the present insention which is to be defined by the appended claims.
