Note: Descriptions are shown in the official language in which they were submitted.
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1 SHOE AND METHOD OF MAKING SAME
2 The present invention relates, in general, to footwear, and more
particularly
3 to a footwear construction for walking and other active use. The invention
has
4 particular utility in connection with high heel shoes, and will be
particularly
described in connection with such utility, although other utilities are
contemplated.
6 Prior art high heel shoes in current use have a reputation of being
extremely
7 uncomfortable and there is survey information indicating that as many as 20%
of
8 the users of such shoes experience foot pain related to the shoes
immediately and
9 the majority of users experience such pain, after as little as four hours of
use. This
discomfort results primarily from the wearer's foot sliding forwards in the
shoe
11 with the consequence that the wearer's toes are jammed in the toe portion
of the
12 shoe.
13 With reference to Figure 1 there is shown in ghost the bone structure of a
14 foot in a conventional high heel shoe. The foot structure comprises the
heel bones
10 {also known as tarsus), including the talus and calcaneous, the arch
including the
16 cuneiform 11 and the metatarsus 12, and the toe bones or phalanges 13. The
heel
17 bones 10 are supported by the heel seat 19, while the arch extends over the
shank-
18 reinforced midsole region 15 of the shoe to the ball of the foot 16 where
the
19 metatarsus joins the base of the phalanges 13. The ball of the foot
underlying the
heads of the metatarsals, forming the metatarsus, and the phalanges are
supported
21 by the toe region 9 of the shoe.
22 The shoe illustrated in Figure 1 has a heel height of approximately 2
inches.
23 The particular shoe illustrated is based on a U.S. standard ladies' shoe
size 7. The
24 shoe is shown on a ground plane 18 from which the heel height " a" to the
heel seat
19 is measured. The heel seat 19 is inclined upwardly at an angle of
approximately
26 12-15 degrees relative to the ground plane. This angle is referenced "x" in
Figures 1
27 and 3. The shank-reinforced midsole region 15 is angled downwardly and
28 forwardly of the shoe from the heel seat at an angle of approximately 30
degrees
29 relative to the ground plane. This angle is referenced "y" in Figures 1 and
3. In the
toe region of the shoe the great toe is essentially parallel to the ground
plane, but
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1 may be inclined upwardly and forwardly by the upward and forward inclination
of
2 the toe region at an angle of 2-3 degrees relatively to the ground plane 18.
This
3 angle is referenced "z" in Figures 1 and 3.
4 As will be appreciated, a conventional high heel shoe such as shown in Fig.
1 places the wearer's foot essentially on an inclined plane, whereupon the
foot is
6 urged forward into the toe box in standing or walking. This results in
pressure on
7 the ball or forefoot regions and toe jamming which often gives rise to a
burning
8 sensation in these areas of the foot, as well as fatigue and discomfort.
9 Traditionally, shoes have been made with either one of two basic
techniques, slip lasting or board lasting. In slip lasting, an upper typically
is
11 stitched together and then either glued or sewn onto a mid-sole and/or
outsole. In
12 board lasting, the upper is either stitched or glued onto a flat or pre-
shaped board,
13 which in turn is attached to a sole and/or outsole. In order to properly
carry the
14 weight of the wearer without the footwear collapsing, a reinforcement,
known as a
shank, typically made of metal, wood, leather, fiberboard or plastic, is
cemented
16 and/or stitched between the midsole and/or insole board and an outsole.
Some
17 shoe constructions also employ a molded sock liner, and/or a cushioning
insole is
18 provided for cushioning the foot in the shoe. However, while cushioning the
foot
19 in the shoe may provide an initial perception of comfort, cushioning
actually
compromises biomechanical properties of the shoe and does little to stabilize
the
21 foot in the shoe or support the foot in an anatomically correct position.
22 It is therefore an object of the invention to provide a shoe having a
23 construction which is comfortable to wear, but which also supports the
wearer's
24 foot in the shoe in an anatomically correct position.
Another object of the present invention is to provide a shoe construction
26 method which provides a shoe construction which is comfortable to wear, but
27 which also supports the wearer's foot in the shoe in an anatomically
correct
28 position.
29 Yet another object of the present invention is to provide a means for
altering the angle of inclination of the heel in relation to the ground plane.
This is
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1 applicable in a variety of shoe heel heights and would permit the ability to
retain
2 the heel in a near parallel relationship to the ground plane as the heel
height
3 increases as in women's high heeled dress shoes.
4 Still another object of the invention is to provide a shoe construction
which
supports the longitudinal axis of the foot but permits flexibility in the
oblique axis
6 orientation. This would be applicable in the design, e.g. of golf shoes
where
7 flexibility during swing motion could be permitted but collapse of the
longitudinal
8 arch of the foot during walking prevented. In such application, the area
underlying
9 the medial longitudinal arch of the foot would be either thinned down or
completely removed to permit for raising and lowering of the arch of the foot
71 during the swing motion while the central portion would retain its rigid
12 construction to prevent long axis breakdown.
13 Briefly, the present invention in one aspect accomplishes the foregoing and
14 other objects, by providing a shoe construction in which a rigid shaped
orthotic
device comprising a heel cup and an anatomically shaped appliance running
distally
16 to just proximal to the metatarsal heads, is rigidly affixed as a
structural element to
17 the top surface of the last/insole board. The shaped device includes a deep
18 conformal heel cup, and runs from the heel of the shoe to the point just
behind the
19 metatarsal head area, and is molded and/or machined to conform to the
underside
of the foot whereby to cause the foot to assume an anatomically correct
position
21 within the shoe. As thus described, the shaped device of the present
invention is
22 similar to a conventional foot orthotic device; however) unlike
conventional foot
23 orthotic devices, the shaped device of the present invention comprises an
integral
24 structural element of the shoe, whereby to better stabilize the wearer's
foot in the
shoe, and preferably eliminate the need far a separate shank, and thus may
serve a
26 dual purpose.
27 As applied to high heel shoes in accordance with a preferred embodiment of
28 the invention, the rigid shaped device includes a heel seat having a
slightly
29 downwardly inclined angle (relative to the shoe's imaginary shank plane),
and an
arch support extending forward from the heel seat and having a first portion
which
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1 supports the head of the navicular of the wearer. The shoe also includes a
2 last/insole board extending downwardly and forwardly from the first portion
of
3 the arch support, and a toe support region which extends at an inclination
4 upwardly and forwardly from the last/insole board whereupon the first
metatarsal
of the wearer is buttressed by the phalanges of the wearer to prevent forward
6 sliding of the foot of the wearer relative to the shoe, thereby preventing
jamming of
7 the human digits into the toe portion of the shoe, while an increase of
about 16% or
8 more of the wearer's weight is borne by the heel seat, as compared to
standard high
9 heel dress shoes.
Still other objects and advantages of the present invention will become
11 apparent from the following description taken in conjunction with the
12 accompanying drawings in which like numerals depict like parts, and
wherein:
13 Fig. 1 is diagrammatic cross sectional view of a conventional high heel
shoe
14 made in accordance with the prior art;
Fig. 2 is a diagrammatic cross sectional view of a high heel shoe made in
16 accordance with the present invention;
17 Fig. 3 is a diagrammatic representation showing a comparison of relevant
18 angles to the ground plane of a shoe made according to the present
invention such
19 as that shown in Fig. 2, and a conventional high heel shoe having similar
heel
heights, i.e. such as shown in Fig. 1;
21 Figures 4-7 are views, similar to Figure 2, of high heel shoes made in
22 accordance with the present invention, and illustrating the application of
the
23 invention to shoes with varying heel heights;
24 Fig 8 is a side elevational view, in partial cross-section, of a shoe made
in
accordance with one embodiment of the present invention;
26 Fig. 9 is an exploded view of the shoe of Fig. 8;
27 Fig. 10 is a perspective view, in partial cross-section, of the shoe of
Fig. 8;
28 Fig. 11 is a perspective view of an element of the shoe of Fig. 8;
29 Fig. 12 is a view, similar to Fig. 8, and showing an alternative embodiment
of the invention;
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1 Fig. 13 is a cross-sectional view taken along lines 13-13 of Fig. 12; and
2 Fig. 14 is a side elevational view showing placement and support of the left
3 foot by the present invention.
4 Referring to Figure 2, there is shown a preferred embodiment of the present
5 invention. As in the case of the shoe of Figure 1, the shoe shown in Figure
2 has a
6 heel height of approximately two inches. However, unlike the conventional
shoe
7 shown in Figure 1, in the Figure 2 shoe, the heel seat 20 is rotated
clockwise, i.e.,
8 in the direction of arrow CL, relative to the shank plane at an angle "H",
relative to
9 ground plane 18, in accordance with the following formula:
H = 5~ + (oc x 1.25~)
11 where oc = the heel height in nearest'/z" segments in excess of 1".
12 An arch support 22 extends forward from the forward edge of the heel seat
13 20 to underlie the arch of the foot of the wearer, at least in part. Arch
support 22
14 has a contour with a high point 23 which forms a barrier which prevents
forward
sliding of the calcaneus of the wearer forward in the shoe. The arch support
22
16 then curves downwardly from the high point 23 to join the shank 24 which
then
17 runs to the toe region 26 of the shoe.
18 Shank 24 is inclined at an angle "M" perpendicular to the ground plane in
19 accordance with the following formula:
M = 18~ + (ac x 3.5~)
21 where oc = the heel height in nearest'/z" segments in excess of 1".
22 Maintaining the aforesaid relationships of "M" and "H" relative to heel
23 height is critical to the present invention in order to prevent excessive
height at
24 point 23 which would be uncomfortable to the wearer. Thus, altering the M/H
relationship as heel height ac increases, results in a shift of the weight of
the wearer
26 onto the heel seat, thus preventing forwarding sliding in the shoe, but
without
27 creating a painful stress point under the arch of the wearer.
- 28 The toe region of the shoe is inclined upwardly and forwardly by the
29 upward and forward inclination at an angle 'T" of approximately 2-3~
plus/minus
1~ relative to the ground plane.
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1 The combination of the downward inclination of the heel seat, the contour
2 of the arch support 22 as an extension of the heel seat, the incline of the
shank, and
3 the upward inclination of the toe region of the shoe, i.e. in accordance
with the
4 present invention, results in higher percentage of the weight of the wearer
being
carried by and supported by the heel seat than in the case of a conventional
high
6 heel shoe. Pressure measurements taken within the shoe under the wearer's
heel
7 seat and balls of the foot, respectively, of a high heel shoe made in
accordance with
8 the present invention, and a conventional high heel shoe of equal heel
height, show
9 a shoe made in accordance with the present invention provides an increase in
the
weight carried by the wearer's heel of approximately 16 - 18%, with a
11 corresponding decrease in the weight carried by the ball of the foot of the
wearer,
12 during walking. Thus, as a consequence of a design of the shoe of the
present
13 invention, a greater portion of the weight of the wearer is borne by the
heel seat
14 rather than being transferred by the sloping shank of the shoe to the ball
of the
foot, toe jamming is prevented, and comfort assured.
16 Referring to Figure 3 the line in ghost illustrates the heel seat angle H,
the
17 inclination M of the first metatarsal and of the great toe T in the toe
region relative
18 to the ground plane 18 of a high heel shoe made in accordance with the
present
19 invention. Dimension oc represents the heel height. The solid line in
Figure 3
represents the corresponding set of angles and inclination for currently
available
21 high heel shoes having similar heel heights such as shown in Figure 1 to
that of the
22 present invention. In these current shoes the inclination of the heel seat
is upward
23 towards the rear of the shoe at an angle x of approximately 8 degrees, the
24 inclination of the first metatarsal downwardly and forward is at an angle y
of about
27 degrees and the great toe is inclined upwardly and forwardly at an angle z
of
26 approximately 1 '/z degrees. These angles are also relative to the ground
plane 18,
27 and relate to a shoe of similar size.
28 A brief explanation of the mechanics of the foot rnay be helpful to
facilitate
29 an understanding of the function of the shoe of the present invention. The
foot is
capable of functioning in two separate mechanical fashions so as to support
the
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1 body above. Primarily, the foot functions as a beam and supports the body by
2 bending strain. This mechanism of support is effective when the force in
acting on
3 the arch (arch flattening force) is relatively low. This occurs at such
times in the
4 step when the center of body weight falls posterior (behind) the ankle
joint. As the
center of weight passes ahead of the ankle joint, as occurs in a normal step
forward,
6 the forces present begin to cause arch flattening. To counter this, the foot
initiates
7 a basic change in the mechanism of support to a truss form of support and is
then
8 capable of supporting via compression strain. Since the bones of the faot
have been
9 shown to be extremely strong in terms of compression strength, the greater
the
1Q compression strain, the better the arch support ability. In order for the
foot to
11 achieve this change in support mechanism, the metatarsals must be
buttressed by
12 the bending of the toes. This buttress effect prevents the metatarsals from
sliding
13 forward and thus permits the switch from bending to compression support.
14 It is the combination of this effect and the shape and inclination of the
heel
seat and arch support in the shoe design of the present invention that
provides the
16 advantages of the present invention. By creating a particular platform
surface for
17 the foot, a buttress effect is initiated in a more effective fashion
preventing the
18 forward sliding of the metatarsal bones and, as a result, eliminating the
subsequent
19 jamming of the toes into the pointed front of the shoes.
Increasing the angle of bending, dorsiflexion of the toes in the shoes can be
21 accomplished in one of two ways. The tip of the shoes may be lifted upwards
22 creating a "genie" type shoe. Although this would be effective, it would
not be
23 particularly stylish. A more effective mechanism entails increasing the
angle at
24 which the metatarsals themselves approach the sole of the shoe. This has
the effect
of increasing the bending of the toes without creating a "genie" type shoe.
This
26 increase in the angle of the metatarsals relative to the ground plane is
accomplished
27 by the change in the rear construction of the shoe, specifically the angle
of the heel
28 seat, and by extending the arch support under the navicular of the wearer
as
29 previously discussed. Since the foot is jointed in a variety of locations,
the plane
that the heel bone (calcaneus) takes with the ground will be compensated for
by the
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1 pitch of the metatarsals as they approach the ball of the foot. This angular
2 relationship is inversely proportional. The closer the calcaneous comes to
parallel
3 with the ground (provided there is adequate heel height present), the closer
the
4 metatarsals approach a perpendicular attitude. Thus, by providing a heel
seat with
a low slope to increase the descent angle of the metatarsal, the desired
buttressing
6 effect is achieved.
7 In the present invention, the heel seat is maintained downwardly inclined
8 with respect to the shank irrespective of the heel height, and the navicular
of the
9 wearer is supported by an arch support extending forward from the heel seat.
In
prior art shoe designs, the higher the heel of the shoe, the closer the heel
seat angle
11 approaches the shank angle. This relative relationship in prior art shoe
designs
12 created an inclined platform of the foot toward the floor. This increased
angle in
13 turn forced the foot to slide forward and be pinched in the toe portion of
the shoes.
14 The present invention creates a shoe in which the heel seat is downwardly
inclined
relative to the shank regardless of heel height, and provides an arch support
which
16 underlies and supports the navicular of the wearer, thereby creating a
surface which
17 causes a greater percentage of the wearer's weight is carried by the heel
seat. The
18 metatarsal angle (corresponding to the shank of the shoe) increases
proportionally
19 to the heel height, e.g. the higher the heel, the greater the metatarsal
angle to the
floor. In a shoe with a heel height over 2 inches, the advantage is not of
increased
21 metatarsal inclination, but rather the resulting biomechanical change in
metatarsal
22 inclination due to the maintenance of heel seat more closely aligned to
parallel to
23 the ground plane.
24 This effect is emphasized when the toe region is angled as specified above
in
-order to increase the spring angle of the toes. As a consequence of this
particular
26 design, the load distribution between the foot and the shoe is effected
whereby
27 when the wearer is at rest a greater proportion of the weight of the wearer
is borne
28 by the heel seat rather than being transferred by the sloping surface of
the prior art
29 shoes to the ball of the foot with consequent problems as referred to
above. Thus,
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1 with the design of the present invention, toe jamming is prevented and
comfort
2 assured.
3 While the description above has been made with respect to a U.S. standard
4 ladies' shoe size 7, having a 2 inch heel height, the invention is
specifically designed
to be applicable to the whole usual range of U.S. standard ladies' shoe sizes
and
6 particularly to those in the range having from size 5 to size 10, and having
various
7 heel heights and particularly to those heel heights that range from 1 to 3
inches.
8 With different shoe sizes and heel heights, the metatarsal inclination will
vary
9 within the range of about 18 - 22 degrees in the case of a 1 inch heel
height to about
33 - 36 degrees in the case of a 3 inch heel height. Figures 2 and 4-7 and the
11 following Table I illustrate high heel shoes made in accordance with the
present
12 invention, and having heel heights of 1 inch (Figure 4), 1 '/z inches
(Figure 5), 2
13 inches (Figure 2), 2 'h inches (Figure 6), and 3 inches (Figure 7.)
14 TABLE I
Heel Seat Metatarsal
Heel Height Inclination An le M Toe An~le
(oc) (H) (T)
1~~ 5-6% 18-22% i=2%.
1'/z" 6-7% 20-23% 2-3%
2" 7-8% 24-28% 2-3%
2'fz" 8-9%~ 30-33% 2-3%
3" 9-10% 33-36% 3-4%
16 In Figs.8-I1, the primary elements of a shoe made in accordance with
17 another and preferred embodiment of the present invention are shown. The
shoe
18 comprises a last/insole board 100 formed of a dimensionally stable,
flexible material
19 such as leather, fiberboard, a non-woven material, or the like. Below the
last board
110 is an outsole 112 and a heel 114. Located above the last board 1l0 is a
rigid
21 device 116 comprising an heel cup l18 and an anatomically shaped arch
appliance
22 120 extending forwardly from the heel cup 118 to just behind the metatarsal
head
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1 area 122. Device 116 is molded and/or machined to conform to the underside
of
2 the foot whereby to locate and stabilize the heel of the wearer in the shoe,
and is
3 racked downwardly from the heel cup 16, i.e. at about 5-10~, depending on
the heel
4 height, so as to cause the foot to assume an anatomically correct position
in the
5 shoe, while the heel of the wearer is retained in a near parallel
relationship to the
6 ground plane, whereby to buttress the phalanges of the wearer to prevent
forward
7 sliding of the foot of the wearer relative to the shoe, i.e. as described in
detail above.
8 Device 116 is adhesively and/or mechanically, e.g. riveted or fixed to
last/insole
9 board 11d.
10 Device 116 can be formed of a lightweight, rigid material compatible with
11 shoe construction. Thus molded device 116 preferably is formed of ABS
plastic;
12 however, device 116 may be formed of other rigid plastic molding materials
or a
13 composite material such as a fiber reinforced plastic or a metal such as
foamed
14 aluminum. Device 116 serves the dual purpose of locating and stabilizing
the
wearer's foot in the shoe, whereby to support the foot in an anatomically
correct
16 position and provide torsional stability, and also serves to stiffen the
shoe from the
17 heel forward to just behind the metatarsal head area, and support the
weight of the
18 user. Thus, the requirement for a separate reinforcing shank may be
eliminated.
29 However, the shoe also may incorporate a reinforcing shank, if desired.
Also,
because device 116 is an integral part of the shoe, its exact location in the
shoe, and
21 thus the location of the wearer's foot in the shoe is assured.
22 Completing the shoe is an insole or sock 124 which is placed over molded
23 device 116, and a shoe upper indicated generally at 126. Heel 114 is
attached to the
24 outsole 112 by means of adhesive and/or mechanical fasteners in known
manner,
while upper 126 is affixed to the bottom of last/insole board 110 and outsole
112 by
26 means of stitching, adhesives, staples, rivets, or combinations thereof
using one of
27 several well known shoe construction techniques.
28 The invention is susceptible to modification. For example, outsole 112 and
29 heel 114 may be formed as a single unit, as shown in Fig. 9. Also, as shown
in Fig.
12, the device 116 advantageously may be employed in a low heel shoe 130 or
boot.
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1 For such application, device 116 will be raked only slightly downwardly from
the
2 heel cup 116 so as to accommodate the lower heel height, while the heel is
retained
3 in a near parallel relationship to the ground plane. Also, device 116 could
be
4 adjusted for different user applications, e.g. golf shoes, so as to provide
the desired
degree of torsional stability as well as anatomically holding the foot in
position,
6 while maintaining shoe structural integrity. For example, as applied to golf
shoes,
7 the area 132 underlying the medial longitudinal arch of the foot may be
thinned so
8 as to permit for raising and lowering of the arch of the foot during the
swing
9 motion, while the central portion would retai n its rigid construction to
prevent
long axis breakdown. Device 116 also advantageously may be employed in men's,
11 women's and children's walking and running shoes, tennis shoes, hiking
boots,
12 cross-training shoes, sandals and other active footwear in which torsional
stability is
13 desired.
14 Although the present invention has been illustrated in terms of a preferred
embodiment, numerous modifications may be made without departing from the
16 spirit and scope of the invention. For example, as shown in phantom in Fig.
11, a
17 cut-out area 140 may be removed from device 116 underlying approximately
the
18 distal 1/3 of the first metatarsal head. Therefore) the scope of the
invention is to be
19 limited only by the appended claims.
