Note: Descriptions are shown in the official language in which they were submitted.
CA 02586360 2007-05-08
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ORTHOTIC ASSEMBLY HAVING STATIONARY HEEL POST
AND SEPARATE ORTHOTIC PLATE
BACKGROUND OF THE INVENTION
a. Field of the Invention
The present invention relates generally to orthotic
devices for use in shoes, and, more particularly, to an
orthotic insert in which there is a stationary heel post
and a separate plate member which is pivotable thereon so
as to provide a controlled range of motion for the foot.
b. Background Art
Orthotic devices have long been employed with
considerable success to treat conditions or otherwise
enhance the functions of the human foot, whether for
ordinary walking or for various forms of specialized
activities, such as skiing, skating, running and so on.
One form of such device has been a built-up structure
in which there is a generally rigid, but' still somewhat
resiliently flexible plate, which usually extends from the
heel of the foot to the metatarsal head area (i.e., the
area beneath the metatarsal heads of the five phalanges),
and a thick, vertical post which is fixedly mounted to the
heel end of the plate. Typically, the orthotic plate is
constructed of a thin, generally rigid material, such as
fiberglass or graphite-resin composite, polyurethane, or a
similar material, while the post is frequently formed of a
hard material which is capable of supporting the rear foot
under the high compressive loads which are developed at
heel strike.
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Such orthotic devices generally serve to both
initially position the foot and then control the. foot's
motions as it progresses through the gait cycle, e.g., a
normal foot should roll (frontal plane motion) about 4 -6
when walking, and perhaps 200-300 when running. To
control the motion of the foot, the plate member flexes
resiliently to a controlled degree, and also there is
often a need to impart a degree of rocking or
eversion/inversion motion of the heel post as well,
depending on the demands of the needs of the individuals
foot/gait and the intended use. For example, for a high-
impact running gait, it is often desirable to effectively
increase the inversion of the rearfoot at heel contact, so
as to increase the total amount of pronation and therefore
the total amount of motion which is available for the
balance of the gait cycle.
To adjust the rear foot angulation, and also in those
instances where the heel post is supposed to move within
the shoe, a common practice has been to grind off or
otherwise remove material from the bottom of the heel
post, in the area where this engages the insole. For
example, FIG. 4 shows an exemplary-prior art orthotic
device 01, in which a portion of the heel post has been
ground off to form a secondary planar surface 03 on the
lateral underside of the post. This provides the post
with a "bi-planar" bottom, so that it pivots through a
controlled angle e0, from a first position in which the
main bottom surface 04 rests generally flat on the plane
05 of the insole, to a second position in which the
upwardly angled surface 03 rests on the insole: For
example, at heel strike the rearfoot is generally inverted
and the weight is borne mostly on the lateral side of the
heel, so that the secondary surface 03 is pressed against
the base plane 05, and then as the foot pronates and the
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weight shifts forwardly and medially, the device rocks
onto the main post surface 04.
The purpose of the rocking motion of the heel post is
to impart this motion to the plate member 06 which is
mounted to the top of the post, the plate member being the
component which actually bears against and engages the
plantar surface of the person's foot. For several
reasons, however, the operation of such devices is
frequently less than satisfactory.
For example, achieving the correct pivoting motion is
highly dependent on the engagement between the bottom
surface of the post and the underlying insole, but the
contours of most insoles tend to be irregular and vary
greatly from shoe to shoe; in an effort to provide a
uniform surface for the post, some practitioners have
resorted to filling in the heel area of the insole to
provide a more or less flat, uniform surface, but this is
an expensive and time-consuming process, and also modifies
the shoe so that in some instances it can no longer be
used without the orthotic.
Furthermore, the rearward portion of the device must
have sufficient clearance between it"and-the interior of
the shoe to allow for the pivoting motion (or else the
edge of the device will rub against the inside of the
shoe), but where the heel counter of the shoe is
particularly tight it may not be possible to establish
this clearance, at least without having to modify the
device to the point where it is ineffective or
uncomfortable to wear. Even in those instances where the
heel counter is sufficiently large or loose to accommodate
the device, time-consuming trimming and grinding of the
device is often necessary to establish the proper motion.
Moreover, even when such devices do function as
intended, the results have generally been less than ideal
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from a biomechanical -standpoint. In particular, the
pivoting motion of the post, back and forth between the
two positions, is somewhat abrupt and irregular in nature,
whereas a smoother, more uniform motion would be
preferable from the standpoint of both function and user
comfort.
Yet another problem which is inherent in conventional
posted orthotic devices of the type which has been
described above is that fabrication of the built-up
structure is notably labor-intensive and expensive from a
manufacturing perspective. As was noted above, the plate
is frequently formed of a thin, hard material, such as
fiberglass or graphite-fiber resin material, while the
post is commonly formed of hard rubber or something
similar. In order to establish a bond between these two
components which will be sufficiently strong and durable
to withstand repeated impacts and distortions without
separating frequently requires the use of relatively
specialized and expensive adhesive compounds. Moreover,
extensive and painstaking surface preparation is often
necessary in order for these adhesives to work properly,
typically involving grinding or otherwise abrading one or
both surfaces, applying both primary and final coats of
adhesive, heating the components in an oven, and so on.
As a result, the need to fixedly mount the post to the
orthotic plate adds significantly to the cost of the
product.
Accordingly, there exists a need for an orthotic
device in which the motion of the plate member which
engages the plantar surface of the foot is generated
independently of and without being affected by any
irregularities or differences in contour which may exist
in the heel area of a shoe insole. Furthermore, there
exists a need for such an orthotic device in which such
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motions in a significantly smoother, more uniformed
manner. Still further, there exists a need for such an
orthotic device which eliminates the need for gluing or
otherwise mounting the post and orthotic plate to one
another.
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SUMMARY OF THE INVENTION
The present invention has solved the problems cited
above, and is a two-piece orthotic insert assembly for use
in a shoe; as used herein, the term shoe includes all
forms of footwear having an insole for supporting a
wearer's foot.
Broadly, the orthotic assembly comprises: (a) a post
member for substantially stationary mounting in a heel
portion of a shoe, the post member having a generally
concave upward bearing surface, and (b) a plate member for
engaging a plantar surface of a wearer's foot in the shoe,
the plate member being substantially free from fixed
attachment to the post member and having a generally
convex lower bearing surface on a heel portion thereof for
resting on the concave upper bearing surface, so as to
support the plate member for pivoting on the post member
through a predetermined range of motion. The upper and
lower bearing surfaces may each comprise a bearing surface
which is substantially continuously curved, so that the
surfaces cooperate to generate a smooth, substantially
uniform pivoting motion between the- first and second
limits of the range of motion. -
The plate member may comprise a thin, substantially
rigid plate member having a heel cup portion formed
proximate the heel end thereof. The plate member further
comprise a forward end portion which is configured to
extend in a frontal plane beneath a forefoot portion of
the wearer's foot.
The concave upper bearing surface of the post member
may comprise a generally U-shaped bearing zone which
extends around a heel end of the post member for engaging
the lower bearing surface on the plate member in pivoting
relationship therewith. The post member may further
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comprise a downwardly extending recess formed in a central
portion of the concave bearing surface for relieving
contact pressures between the bearing surfaces in an area
directly below the calcaneus of a wearer's foot, with the
U-shaped bearing zone extending generally around the
perimeter of the recess.
The medial and lateral side portions of the U-shaped
bearing zone may lie generally within a first plane which
extends at a predetermined angle to the insole of the
shoe, the heel cup portion of the plate member being
configured to support a heel of a wearer's foot at an
initial angle which corresponds to the angle between the
first plane and the insole. The assembly may further
comprise means for selectively adjusting the angle at
which the wearer's heel is supported by the plate member,
and this means may comprise at least one wedge member
which is selectively mountable to a bottom of the post
member so as to adjust the angle between the first plane
and the insole of the shoe.
The first limit of the range of motion of the plate
member may be an initial, inverted angle at which the
wearer's rearfoot is positioned at approximately heel
strike, and the second limit may be a' second, everted
angle to which the wearer's rearfoot shifts following heel
strike.
The assembly may further comprise means for
selectively adjusting the rate of rotation of the plate
member at the second limit o'f the range of motion. This
means may comprise a ramp portion on a medial side of the
concave bearing surface of the post member, the ramp
portion having a predetermined angle of incline for
bearing against the lower bearing surface on the plate
member proximate the second limit of the range of motion.
The assembly may further comprise means for selectively
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adjusting the angle of incline of the ramp portion, this
means may comprise at least one wedge member which is
selectively mountable to the medial side of the lower
bearing surface so as to build up the angle of incline of
the ramp portion.
The post member may also comprise an extension
portion of the lower bearing surface which extends
forwardly under a lower surface of the arch portion of the
plate member, so as to support the arch portion of the
plate member as the weight of a person's foot moves onto
the arch area. The post member may be formed of a firm,
substantially incompressible material, or the post member
may be formed of a soft, resiliently collapsible material
so as to absorb shock loads generated by a wearer's foot
at heel strike. The extension portion under the arch area
may be softer or more rigid depending on the needs of the
individual foot.
The present invention also provides a method for
positioning and controlling motions of a wearer's foot in
a shoe, comprising the steps of: (a) mounting a
substantially stationary post member in a heel portion of
a shoe, the post member having a generally concave upper
bearing surface, and (b) placing in tfie shoe a plate
member for engaging a plantar surface of a wearer's foot,
the plate member being substantially free from fixed
attachment to the post member and having a generally
convex lower bearing surface on the heel portion thereof
for resting on the concave upper bearing surface of the
post member, so as to support the plate member for
pivoting on the post member through a predetermined range
of motion.
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According to one particular aspect of the
invention, there is provided an orthotic assembly
which is detachably mountable to a shoe, said
orthotic assembly comprising an orthotic insert
having at least one recess formed in a lower surface
thereof; at least one locating plug having an upper
end for being received in said recess in said insert
in detachable engagement therewith; and means for
mounting said locating plug to an insole of a shoe so
that said plug detachably retains said insert in a
predetermined position within said shoe.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the two-part orthotic
assembly of the present invention, showing the separate
heel post and rigid plate members of the assembly;
FIG. 2 is an elevational view showing the orthotic
assembly of FIG. 1, as installed in an exemplary right-
foot shoe;
FIG. 3 is a plan, somewhat schematic view of the
human foot, showing the general path which is followed by
the downward weight on the foot, from the lateral side of
the heel at heel strike, towards the medial side of the
foot following heel strike;
FIG. 4 is a cross-sectional view looking forwardly
from the rear of an exemplary prior art orthotic device in
which the post is fixedly mounted to the bottom of the
orthotic plate;
FIG. 5 is another cross-sectional view, looking from
the rear forwardly, of an orthotic assembly in accordance
with the present invention, showing the two-piece
construction having separate heel post and plate members,
and the manner in which the plate member is free to pivot
against the concave upper surface of the post member;
FIG. 6 is a top, plan view of a separate post member
in accordance with the present invention, showing the
generally U-shaped bearing zone on the concave upper
surface of the post member, and the subcalcaneal recess
which relieves contact pressures between the surfaces in
the area directly beneath the heel cup;
FIG. 7 is a bottom, plan view of the post member of
FIG. 6, showing the uniplanar bottom surface and the
contours around the heel end thereof;
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FIG. 8 is a front, elevational view of the post
member of FIGS. 6-7, showing the concave upper bearing
surface thereof;
FIG. 9 is a rear, elevational view of the heel post
member of FIGS. 6-8, showing the outer wall of the member
around the heel end thereof;
FIG. 10 is a right side elevational view of the
right-foot post member of FIGS. 6-9, looking from the
lateral towards the medial side thereof;
FIG. 11 is a left side elevational view of the heel
post member of FIGS. 6-10;
FIG. 12 is a top, plan view of a rigid, resiliently
flexible plate member in accordance with the present
invention, with the dotted line image showing the manner
in which this fits into and engages the post member of
FIGS. 6-11;
FIG. 13 is a rear, elevational view of the plate
member of FIG. 12, showing the heel cup area thereof which
engages the corresponding concave upper surface of the
heel post member in accordance with the present invention;
FIG. 14 is a cross-sectional view, looking from the
rear forwardly, of a two-part orthotic assembly in
accordance with an embodiment of the present invention in
which the inclined medial side of the concave bearing
surface serves to control the range of rearfoot motion
which is allowed by the assembly;
FIG. 15 is a cross-sectional view, similar to
FIG. 14, showing the plate member fitted in engagement
with the generally concave upper surface of the post
member of FIG. 14;
FIG. 16 is a rear, cross-sectional view, similar to
FIG. 15, showing an embodiment of the invention in which
the rearfoot motion is adjustable by means of wedges of
selected sizes which are mountable within the interior of
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the concave bearing surface so as to control the pivoting
motion of the plate member therein;
FIG. 17 is an end, cross-sectional view similar to
FIG. 15, showing the initial angulation of the rearfoot
which is provided by the two-piece assembly of the present
invention;
FIG. 18 is a rear, cross-sectional view, similar to
FIG. 17, showing the manner in which the angulation of the
rear foot is adjustable by adding one or more wedges to
the planar bottom of the heel post member;
FIG. 19 is a top, plan view, similar to FIG. 6,
showing an embodiment of the present invention in which
the U-shaped bearing zone of the heel post member is
enhanced or provided by a raised ridge which extends
around the interior of the concave surface thereof;
FIG. 20 is a rear, cross-sectional view, similar to
FIG. 7, showing the manner in which the U-shaped ridge of
the post member of FIG. 18 cooperates with a corresponding
ridge on the bottom of the plate member so as to support
the heel cup of the plate member at it predetermined
initial angle;
FIG. 21 is a cross-sectional view, similar to FIG.
20, showing an embodiment in which str'ips forming the
ridge on the bottom of the plate member are selectively
mountable thereon so as to adjust the initial angle of the
heel cup;
FIG. 22 is a cross-sectional view, similar to
FIG. 20, showing the manner in which the initial
angulation of the rear foot can be adjusted by adjusting
the position of the U-shaped ridge within the post member;
FIG. 23 is a side, cross-sectional view of the rear
foot portion of a shoe and orthotic assembly in accordance
with an embodiment of the present invention in which the
plate member has a downwardly projecting transverse ridge
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which engages a corresponding groove in the post member to
prevent the plate member from sliding forwardly in the
shoe;
FIG. 24A is a top, plan view of the post member of
the orthotic assembly of FIG. 23, showing the transverse
groove which is formed in the upper surface thereof;
FIG. 24B is top, plan view of the rear foot portion
of the plate member of the orthotic assembly of FIG. 23,
with the dotted line image showing the downwardly
projecting, transverse ridge thereon which engages the
groove and the post member;
FIG. 25 is a side, cross-sectional view of the rear
foot portion of a shoe and the post member of an orthotic
assembly in accordance with the present invention in which
the post member is held in position in the shoe by a plug
member which is mounted to the top of the insole and which
fits within the corresponding opening and the post member;
and
FIG. 26 is a perspective view of an exemplary sandal,
showing the manner in which an orthotic device may be
mounted and held in position therein using a plug member
similar to that which is shown in FIG. 25.
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DETAILED DESCRIPTION
a. Overview
FIG. 1 shows an orthotic assembly 10 in accordance
with the present invention. As can be seen, this
comprises two major components, a post member 12 having a
generally concave upper surface 14, and a separate plate
member 16 have a generally proximal lower surface 18 which
fits into and engages the concave upper surface of the
post member so as to allow a pivoting or "rocking" motion
between the two pieces.
The plate member includes a heel cup area 20, the
upper surface of which engages the plantar surface of the
wearer's rear foot, an arch portion 22 which extends
beneath the arch of the foot, and a forward end 24 which
engages the plantar surface of the forefoot area; in the
embodiment which is illustrated, the forward edge 24 is
configured to lie generally beneath the metatarsal head
area of the foot, so as to lie generally flat with the
frontal plane of the foot in the later phases of the gait
cycle. The plate member can be formed of any suitable,
generally rigid material, with a thin, rigid, resiliently
flexible material being preferred; fiberglass-resin and
graphite fiber-resin materials are eminently suitable for
this purpose, and cast urethane, various plastics, various
metals, and other suitable materials may also be used in
various embodiments. Also, although not shown in FIG. 1,
the plate member may include a cushioning top cover for
added wearer comfort.
The post member 12, in turn, is configured to receive
and engage the rear foot portion of the plate member. As
was noted above, this has a concave upper surface 14,
which engages the corresponding convex surface 18 on the
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bottom of the plate member. The concave upper surface is
located a predetermined, spaced distance above the flat,
generally planar bottom surface 26 of the post member, the
latter being configured to rest in a stationary position
atop the insole of the shoe.
The rearward perimeter wall 28 of the post member
follows a generally U-shaped contour which is configured
to generally match the heel counter of the shoe, and a
transverse forward wall 30 extends across the front of the
member. As will be described in greater detail below, the
forward wall 30 preferably extends at an angle to the long
axis of the device (as opposed to being at a right angle
thereto), so that the forward medial corner 32 of the post
member projects to a somewhat more forward position than
the lateral corner 34.
A downwardly extending recess 36 is preferably formed
more or less centrally in the concave upper surface 14 of
the post member, so as to be positioned generally beneath
the calcaneus of the wearer's foot. As will also be
described in greater detail below, this serves to reduce
contact pressures beneath the plate and post members at
the bottom of the heel cup, so that-the plate member is
supported by the top of the post member along a generally
U-shaped, peripheral zone which extends around the heel
end of the device, so as to facilitate the positioning of
the rear foot and the pivoting motion of the plate member.
A generally circular or oval recess is shown in FIG. 1,
however, it will be understood that the recess may have
any suitable shape, and may be open to the edge or bottom
of the post member in some embodiments. Also, in some
embodiments the plate may have a corresponding hole formed
through it which is positioned generally in register with
the underlying recess in the post member so as to
completely off-load a given area of the heel, e.g., for
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accommodation of a heel spur or other condition of the
f oot.
The body of the post member may be formed of any
suitable material having sufficient compressive strength
to form the upper concave surface and to perform the rear
foot angulation and other functions described herein, with
hard rubber being eminently suitable for this purpose; in
some embodiments, the post member may be formed in whole
or in part of a lower durometer rubber, foam or other
resiliently compressible material, so as to provide a
degree of cushioning for the foot during heel strike and
the initial phases of the gait cycle. It will be
understood, however, that low-friction bearing surfaces
will generally be preferred in order to facilitate the
pivoting action of the plate member.
When the assembly 10 is placed in a shoe 40 as shown
in FIG. 2, the post member 12 resides in a stationary
position within the heel counter 42, with its bottom
surface 26 resting more-or-less flat on the insole 44.
The heel cup 20 of the plate member rests within and is
supported by the concave upper surface of the heel post,
but remains free to pivot from side" to-side, i.e., to
invert and evert about the long axis of t'he foot therein.
The forward edge 24 of the plate member, in turn, rests
against the insole in the forefoot area of the shoe,
generally in the area beneath the metatarsal heads.
As is shown in FIG. 5, the radii R1 and R2 of the
surfaces 18 and 14 of the plate member and post member are
selected to permit a predetermined degree of side-to-side
pivoting or rocking motion to develop between the members,
as indicated by arrows 46, as the wearer's foot through
the gait cycle. As was noted above, and as is shown in
FIG. 3, during the initial phases of the gait cycle the
wearer's rear foot is generally somewhat inverted
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(generally, the foot is balanced when it is about 4
inverted) and the weight is borne towards the lateral
side, in the area indicated generally at 50. As a result,
the plate member 16 is shifted towards the right in FIG. 5
(i.e., towards the lateral aspect of the rear foot) when
the heel touches down. Then, as the foot progresses into
the gait cycle, the rear foot everts and the weight shifts
along path 52 towards the medial side, as indicated at 54
in FIG. 3, until the medial forefoot comes down against
the insole along the frontal plane of the foot (typically,
at about the 25% point in the gait cycle) As a result,
the plate member shifts towards the left (i.e., medial
side) in FIG. 5, until the motion of the foot is arrested
after a predetermined amount of pronation has occurred.
As will be described in greater detail below, the
initial angulation of the rear foot is controlled by the
angulation of the upper surface 14 of the host member, in
particular the angulation of the general plane in which
the U-shaped bearing zone lies. The amount of motion, in
turn, and therefore the degree of pronation which is
permitted by the device, is limited by engagement of the
under surface 18 of the plate with the medial side of the
concave post member, and also by the dista'1 medial edge 24
of the plate member coming to rest against the insole of
the shoe a long the frontal plane; the manner in which
this range of travel can be adjusted will also be
described in greater detail below.
b. Structure
FIGS. 6-11 show the structure of the heel post member
12 in greater detail.
Firstly, as was noted above, the main load-bearing
engagement between the plate and post members follows a
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generally U-shaped zone around recess 36 and the heel end
of the post, as indicated generally by dotted line 60 in
FIGS. 6 and 8. As can be seen in FIG. 8, the U-shaped
bearing zone lies generally in a plane 62 which is
elevated above a base plane 64 which is defined by the
bottom of the post member and the top of the insole of the
shoe. The angle of the elevated bearing plane 62 relative
to the base plane 64 determines the initial angulation of
the plate member 16, and in turn the initial angulation
(ordinarily inversion) of the rear foot: the angle of the
wearer's rear foot lies generally along an axis which
extends perpendicular to the focus of the heel cup, i.e.,
the central, generally lowermost portion of the heel cup.
In the example which is illustrated in FIG. 8, the
bearing plane 62 extends at an angle of about 4 to the
base plane 64. As a result, an axis 65 which is
perpendicular to the focus of the heel cup of the plate
member extends at an angle of about 4 to an axis 66 which
is perpendicular to the insole of the shoe. Hence, in
this example, the assembly increases the inversion of the
wearer's rear foot by about 4 from its natural position;
in other words, if the natural inversion of the wearer's
rear foot at heel strike is about 4 , the assembly will
increase the total angle of inversion to about 8 . As
will be described in greater detail below, this angulation
is also adjustable in accordance with the present
invention in order to meet the requirements of individual
feet and/or uses.
FIGS. 6 and 7 also show the angled forward edge of
the post member. As can be seen, the forward, medial
corner 32 of the post member is positioned more forwardly
than the lateral corner 34, so that a line 70 drawn
between the two defines an angle a with a line 72 which
extends perpendicular to the long axis of the assembly.
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The effect of this angulation is to form an extension 74
of the bearing surface on the medial side of the post
member. This provides the rearward end of the arch area
of the plate member with additional support and rigidity,
so as to enable the assembly to employ a thin and somewhat
resiliently flexible plate member for maximum comfort and
'control. It has found that an edge angle a of about 5-15
is suitable for this purpose, with an angle of about
10-15 being generally preferred.
The angled forward edge of the post member also
results in an increased wall length at the front of the
post, where this engages the insole, so as to create an
enhanced "buttress" effect which helps to prevent the post
member from sliding forwardly in the shoe. It will be
understood, however, that some embodiments of the present
invention the heel post member may lack the medial
extension, i.e., the forward edge of the post may extend
straight across or some angle other than those that have
been described above. Furthermore, in some embodiments
all or part of the forward edge of the post member may
extend up the sagital plane incline from the rear foot
towards the midfoot, as indicated by dotted line image 75
in FIG. 2, so as to form a somewhat upwardly inclined
forward portion of the concave heel post which will react
against the convex lower surface of the heel cup of the
plate member so as to retain the plate member against
shifting forwardly in the shoe.
The bottom and rear views in FIGS. 7 and 9 also show
an angled cutaway or "skive" 76 which may be provided at
the very heel end of the post member. As can be seen, the
skive forms a generally flat, planar area which extends
from the bottom surface 26 of the post member to near the
upper edge 78 of the member, at a somewhat shallower angle
than the remainder of the perimeter wall 28. The cutout
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provides additional clearance at the heel end of the post,
so as to permit the post member to be fitted very closely
and tightly within the heel counter in FIG. 2 (some space
is shown between the rear of the post member and the heel
counter of the shoe, however in most instances the post
member will be installed tight against the heel counter.
Again, however, it will be understood that this feature
may not be present in some embodiments of the invention.
FIGS. 12-13, in turn, show the plate member 16 in
greater detail, and the manner in which this fits into the
post member 12, as indicated by the broken line image in
FIG. 12. FIG. 12 shows the post member being somewhat
wider than the rear foot portion of the plate member,
however, it will be understood that the width of the post
member may be wider, equal to, or narrower than the rear
foot portion of the plate member, depending on the design
of the shoe, the nature of the individual foot, and other
considerations.
From the standpoint of operation of the assembly, the
principal features of the plate member are the generally
convex rear foot bearing surface 18, which engages and
pivots on the corresponding surface in the heel post
member, and the generally flat lower surface 80 of the
forefoot end 24, which extends parallel to the frontal
plane when the medial forefoot comes to rest against the
insole. The arch area and the contoured upper surface of
the plate member are configured to engage and support the
plantar surface of the wearer's foot, but may vary
somewhat from one assembly t.o the next; for example, the
arch portion may be more pronounced for assemblies which
are designed for activities which require greater support
in this area, or the arch portion may be more steeply or
less steeply down-curved depending on the intrinsic
anatomy of the individual foot or the type of shoe with
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which the device is to be used (e.g., a women's "pump" may
require a more steeply down-curved arch portion than a
low-heeled shoe).
c. Operation and Adjustment
Because the motion of the plate member, and therefore
that of the wearer's foot, develops at the interface
between the surfaces 14, 18 of the post and plate members,
the function of the orthotic assembly of the present
invention is not dependent on or affected by the contour
of the shoe insole. The assembly is therefore able to
function effectively in a wide variety of shoes, without
requiring the painstaking and time-consuming grinding and
shaping which is commonly involved in the fitting of prior
art devices. Furthermore, the use of separate foot post
and plate members eliminates any need to join these
together using adhesives or other techniques.
Moreover, because both of the bearing surfaces (i.e.,
the top surface of the post member and the bottom surface
of the plate member) are curved--unlike the generally flat
surface of' the insole--the assembly is able to generate a
very uniform motion, without abrupt transitions or stops
during or at the limit of travel.
The range of motion in the direction of
eversion/pronation is controlled primarily by the forward
end of the plate member coming to rest against the insole
along the forefoot plane, the action of the convex bottom
of the plate member coming up against the medial side of
the concave post member, in turn, can be used to increase
or decrease the resistance to the motion in the terminal
phase of roll/pronation, thereby slowing the rate of
pronation to a great or lesser degree: In general, a
slower rate of roll in the terminal phase is preferably
CA 02586360 2007-05-08
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for a"loose", less stable foot, while a higher rate of
pronation can be used with a more stable foot.
For example, as can be seen in FIGS. 14-15, the rate
of the pivoting motion or "roll" towards the medial side
of the assembly can be controlled by means of the slope
and/or height of a medial ramp portion 84 on the interior
of the post member. The greater the incline of the ramp
portion, the greater the resistance to pronation during
the final phase of the gait cycle: Reducing the angle of
the incline, as indicated by line 86 in FIG. 15, will
allow a higher rate of rear foot motion in the medial
direction, as indicated by arrow 88; conversely, a steeper
incline, as indicated by line 90, will reduce the rate of
motion.
The assembly may also include means by which the
inclination of the medial slope can be selectively
adjusted. For example, as is shown in FIG. 16, one or
more contoured wedges 92 may be adhered or otherwise
mounted to the medial incline so as to selectively build
this up and increase its slope. The wedge members may
have a tapered contour, with the thin edge being
positioned towards the bottom of.- the concave post
surface 14 and the thicker edge being towards the edge of
the post, or other shapes of wedges may be employed,
depending on the application and the intended motion of
the plate member. Moreover, a series of interchangeable
wedge members may be provided, together with a "standard"
shape of post member having a nominal medial incline to
which the customer or a foot care practitioner can add one
or more of the wedges depending on intended use, comfort
or other needs of the individual foot, and so on.
Consequently, this feature provides the device with a high
degree of adjustability at minimal cost.
CA 02586360 2007-05-08
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As was noted above, the angle at which the assembly
positions the wearer's rear foot during heel strike and
the initial phases of the gait cycle can also be adjusted.
For example, FIG. 17 shows a post member similar to that
in FIG. 8, in which the bearing zone (as represented by
arrows 94a, 94b on the medial and lateral sides of the
heel cup) lies in a plane 62 which is generally parallel
to the plane 64 of the post bottom/insole; in this case,
an axis perpendicular to the heel cup generally matches an
axis 96 perpendicular to the insole, i.e., the assembly
adds little or no angulation of the rear foot relative to
the insole.
Then, to selectively increase the angulation, a wedge
or other support can be inserted under one side or the
other of the post member. For example, as is shown in
FIG. 18, a wedge member 98 may be mounted to the bottom of
the post member with its thickest edge towards the medial
side, so as to form a second, angled lower surface 100
which engages the insole so as to shift the plane of the
bearing zone to an increased angle, as indicated at 62a.
This in turn shifts angle of the plate member so as to
increase the inversion of the rear foot, as indicated at
96a, by a predetermined angle O. IE desired for a
particular application, a wedge can be mounted to the
bottom of the post member in a reverse manner, so as to
increase eversion of the rear foot.
Accordingly, by mounting selected wedges to the
bottom of the post member, the initial angulation of the
rear foot can be adjusted as desired. While the amount of
angulation will again depend on the nature of the
individual foot and the intended use of the device, the
angle 6c will typically be in the range from about 0 -8 ,
with an angulation of about 4 -6 being common. Moreover,
a series of adjustment wedges can be supplied for use with
CA 02586360 2007-05-08
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a standard post member so as to be able to increase the
angulation of the rear foot by incremental amounts, e.g.,
2 , 4 , 6 , 8 , and so on. Also, the wedges can be formed
of a material having a stiffness greater than or
comparable to that of the body of the post member, or they
may be formed of a softer, more compressible material to
provide more of a cushioning effect at the end of travel.
FIGS. 19-22 illustrate embodiments of the invention
in which adjustment of the rear foot angulation is
achieved in a somewhat different manner. In these
instances, the U-shaped bearing zone 60 is formed by a
raised rib 110 which extends around the interior of the
concave surface of the post member, this being shown
somewhat exaggerated in the figures for purposes of
illustration. As can be seen in FIG. 20, the medial and
lateral portions il0a, 110b of the raised rib on the post
member react against the medial and lateral portions 112a,
112b of the corresponding raised, downwardly projecting
rib on the bottom of the plate member 16 to position the
rear foot portion of the plate member at a predetermined
degree of inversion at heel impact. Then, following heel
impact, the plate member rotates on.-the post member for
pronation of the foot, in the manner described above.
The upper ridge 112 may be formed an integral part of
the plate member, or as is shown in FIG. 21, the ridge may
be made as a separate piece or pieces (i.e., the medial
and lateral sides of the ridge 112a, 112b may be formed as
two separate strips) which are mountable to the lower
surface 18 of the plate member in a selected position, as
indicated by the arrows in FIG. 21. For example, a
practitioner may be provided with a standard post and
plate member, and then the ridge or ridges 112a, 112b can
be mounted in selected positions to provide a degree of
inclination as needed by an individual foot.
CA 02586360 2007-05-08
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As can be seen in FIG. 22, the angular adjustment can
also be made by changing the position of the raised
rib 110 within the interior of the post member. For
example, in a first configuration, the U-shaped ridge 110
may be relatively level within the post member so as to
define a somewhat horizontal support plane 114, thereby
imparting only a small degree of additional angulation to
the rear foot. To adjust this angulation, the position of
the ridge may be shifted within the post member, as
indicated by dotted line image 110', so that the ridge is
higher on one side (e.g., the medial side) and lower on
the other. This forms a second, angled support plane 116
which shifts the angle of the plate member and thereby
increases/decreases the initial inversion of the rear foot
by a predetermined amount. The raised ridge 110 may be
molded or otherwise formed as an integral part of the post
member, or this may be a separate piece which is adhered
or otherwise mounted to the interior surface of the post
member in a selected orientation.
FIGS. 23 and 24A-24B illustrate an embodiment of the
present invention in which the plate member engages the
stationary post member during use so as to hold the former
in place against shifting forwardly in the shoe. In this
embodiment, a transversely extending ridge 122 projects
downwardly from the bottom surface 18 of the plate
member 16, and is received in a corresponding channel or
groove 120 which is formed in the upper surface of the
post member. Since the post member 12 is mounted firmly
to the insole 44 of the shoe, the engagement between the
groove 122 and the ridge 120 prevents the plate member
from shifting forwardly in the shoe as the person is
walking, while still allowing the plate member to rock
from side to side in order to generate the desired motion.
CA 02586360 2007-05-08
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As can be seen in FIGS. 24A and 24B, the groove 122
and ridge 120 extend generally transverse to the long axis
of the device/shoe, and the groove is preferably sized
somewhat wider than the ridge so as to avoid friction
which would interfere with movement between the two parts.
Also, it will be understood that in some embodiments the
ridge may be formed on the upper surface of the post
member and the groove on the bottom of the plate member,
the reverse of the arrangement which is shown in
FIGS. 24A-24B.
FIG. 25, in turn, illustrates an embodiment of the
present invention in which the heel post member 12 is
removable from the shoe, and is anchored in place by means
of a plug 130 which is attached to the insole. As can be
seen, in this embodiment the central recess 36' extends
completely through the post member, so as to form a hole
which exposes an area 132 of the insole. The plug 130 has
an adhesive lower surface 134, and is sized to pass
through and fit closely within the opening 36'.
Accordingly, to install the assembly in the shoe, the
post member is first fitted into the heel end of the shoe
at the desired location. The adhesive layer of the plug
is then exposed (e.g., by removing a paper or plastic
backing), and the plug is inserted downwardly through the
opening 36', in the direction indicated by the arrow in
FIG. 25, so that the adhesive surface contacts and engages
the area 132 of the insole within the opening. Downward
finger/thumb pressure can be applied as necessary to
insure firm engagement betwe.en the plug and insole, and
the thickness of the plug member is preferably such that
its upper surface rests at or slightly below the top of
the recess 36', as indicated by dotted line image 136 in
FIG. 25. The plug 130 may be formed of any suitable
material, with firm foam material being eminently suitable
CA 02586360 2007-05-08
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for this purpose. Moreover, the plug member may have any
suitable shape, and may also be formed as a plurality of
plugs in some embodiments; also, in some embodiments the
opening for receiving the plug member may be formed as a
recess in the bottom of the post member rather than as a
hole passing completely therethrough.
Once the plug 130 has been attached to the insole 44
in the manner described, this serves to stabilize the post
member 12 and prevent it from shifting within the shoe.
Moreover, as compared to a post which is glued or
otherwise permanently mounted in the shoe, this
arrangement allows the post to be removed and placed in
another shoe at will, thereby enabling the owner to use
the orthotic assembly with more than one pair of shoes.
It will also be understood that in some embodiments the
locating plug may be formed as a permanent part of the
shoe or insole itself; for example, the plug may be formed
as a part of the insole or heel of the shoe, for engaging
and stabilizing a plurality of different insoles or
orthotic devices which are interchangeably mountable in
the shoe.
Moreover, as can be seen in FIG: 26, a locating plug
of this type can be employed to mount a initary, one-piece
orthotic device in a shoe, as well as the two-piece type
system described above. This is particularly advantageous
in the case of sandals and similar types of footwear,
being that the open-ended/sided structure of sandals
(particularly in the heel area) has long presented a
problem as to how to get an orthotic device to stay in
place, yet still be removable so that it can be used with
other pairs of shoes.
Accordingly, FIG. 26 shows a sandal 140 having a
typical open-sided heel end 142. In accordance with the
present invention, an orthotic insert 144 is provided
CA 02586360 2007-05-08
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which is sized to fit within the sandal, and which
includes an opening 146 which is more or less centered in
the heel cup of the device. A corresponding locating
plug 148 is provided which is sized to interfit with the
opening 146, and which is adhered or otherwise mounted to
the top of the sandal insole 150 in a predetermined
position near the heel end thereof, as indicated at 152 in
FIG. 26. As with the two-piece system described above,
correct positioning of the locating plug can be achieved
by first placing the orthotic insert 144 in a selected
position atop the insole of the sandal or other article of
footwear, and then pressing the locating plug 148
downwardly through the opening 146 into adhesive contact
with the surface of the underlying insole. Moreover,
several sets of the locating plugs 148 can be provided so
as to permit the orthotic to be used interchangeably with
multiple pairs of sandals or other shoes.
It is to be recognized that various alterations,
modifications, and/or additions may be introduced into the
constructions and arrangements of parts described above
without departing from the spirit or ambit of the present
invention as defined by the appended claims.
