U.S. patent application number 13/168727 was filed with the patent office on 2011-10-27 for footwear insole.
Invention is credited to Howard Dananberg, Brian G.R. Hughes.
Application Number | 20110258879 13/168727 |
Document ID | / |
Family ID | 45497372 |
Filed Date | 2011-10-27 |
United States Patent
Application |
20110258879 |
Kind Code |
A1 |
Dananberg; Howard ; et
al. |
October 27, 2011 |
FOOTWEAR INSOLE
Abstract
A human shoe sole or insole, sockliner or orthotic for insertion
into a human shoe having a foot supporting upper surface including
a first region for supporting at least the first, metatarsal head
of the foot, and a second region surrounding the first region. The
first region provides less resistance to downward motion than the
second region, and includes a hollow or depressed area, sized and
located to promote eversion of the first metatarsal head as the
wearer moves from midstance through propulsive phase. Also provided
human insole or orthotic for insertion into a human shoe having a
bottom surface with a hard shell covering at least a heel portion
of the bottom surface, which reduces the deformation of the footbed
under load. The insole or orthotic may also include a series of
grooves located to increase flexibility where necessary.
Inventors: |
Dananberg; Howard; (Bedford,
NH) ; Hughes; Brian G.R.; (San Antonio, TX) |
Family ID: |
45497372 |
Appl. No.: |
13/168727 |
Filed: |
June 24, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12534741 |
Aug 3, 2009 |
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13168727 |
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61360412 |
Jun 30, 2010 |
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Current U.S.
Class: |
36/91 ; 36/43;
36/88; 36/92 |
Current CPC
Class: |
A43B 7/148 20130101;
A43B 7/141 20130101; A43B 7/1435 20130101; A43B 7/1445
20130101 |
Class at
Publication: |
36/91 ; 36/43;
36/88; 36/92 |
International
Class: |
A43B 13/38 20060101
A43B013/38; A43B 7/16 20060101 A43B007/16; A43B 7/22 20060101
A43B007/22; A43B 7/14 20060101 A43B007/14 |
Claims
1-61. (canceled)
62. An insole, orthotic or sockliner for insertion into a human
shoe having a foot supporting upper surface having regions of
varying hardness that approximately match the regions of varying
hardness of the underside of the wearer's foot, and a bottom
surface comprising a hard shell covering at least a heel portion of
the bottom surface.
63. The insole, orthotic or sockliner of claim 62, characterized by
one or more of the following features: (a) wherein the hard shell
includes side walls that partially surround the heel portion of the
insole; (b) further comprising an asymmetric heel pad, and
optionally further comprising a depression in the hard shell
corresponding to the asymmetric heel pad; (c) wherein the hard
shell further comprises a frictional surface for preventing
slipping; (d) wherein the bottom surface includes a plurality of
grooves that are located beneath the second, third, fourth and
fifth metatarsal heads of the foot, and forward of the first
metatarsal head of the foot; (e) including a footbed, a lateral
arch region, a medial arch region and a heel region, wherein the
footbed and the lateral arch region have a first hardness value,
the medial arch region has a second hardness value that is softer
than the first hardness value, and the heel region has a third
hardness value that is harder than the first and second hardness
values; (f) wherein the footbed includes a forward region which
includes a hollow or depression underlying the first metatarsal
head of the wearer; and (g) wherein the medial arch region has a
second hardness value that is at least 5 Shore C points softer than
the first hardness value, but not more than 10 Shore C points
softer, and the heel region has a third hardness value that is at
least 10 Shore C points harder than the first hardness values, but
not more than 20 Shore C points harder.
64. An insole, orthotic or sockliner for insertion into a human
shoe having a foot supporting upper surface including a first
region for supporting at least the first metatarsal head of the
foot, and a second region surrounding the first region for
supporting the remainder of the foot, at least in part, wherein the
first region provides less resistance to downward motion than the
second region, wherein the first region includes a hollow or
depressed area relative to the remainder of the first region having
a medial border portion and a lateral border portion, wherein the
depression has its lowest point skewed to the medial side of
center, whereby to promote eversion of the first metatarsal head as
the wearer moves from midstance through propulsive phase, wherein
the depression is formed in a location that is approximately 72.5%
of the length of the length of the insert, measured from the heel,
minus 10 mm.
65. The insole, orthotic or sockliner of claim 64, characterized by
one or more of the following claims: (a) wherein the first region
has a lower durometer than the second region, and wherein the first
region preferably has a Shore A hardness of 30-35; (b) wherein the
first region is formed of a plug of material surrounded by the
second region; (c) wherein the depressed area comprises an opening
formed and extending from the upper foot supporting surface; (d)
wherein the depression comprises a hollow formed below the foot
supporting upper surface; and (e) having a bottom surface that
includes a hard shell covering at least a heel portion of the
bottom surface.
66. An insole or orthotic for insertion into a human shoe having a
foot supporting upper surface, and a bottom surface comprising a
hard shell covering at least a heel portion of the bottom surface,
wherein the bottom surface includes a plurality of grooves located
beneath the second, third, fourth and fifth metatarsal heads of the
foot, and forward of the first metatarsal of the foot, and an
asymmetric heel pad having a depression located beneath the
heel.
67. The insole or orthotic of claim 66, characterized by one or
more of the following features: (a) futher including a plurality of
vent holes connecting the grooves to the upper surface for passing
moisture away from the upper surface; (b) wherein the hard shell
includes side walls that partially surround the heel portion of the
wearer's foot; (c) wherein the depression in the hard shell is tear
shaped; and (d) wherein the depression comprises a hole formed in
the hard shell.
68. A human shoe having a foot supporting upper surface having
regions of varying hardness that approximately match the regions of
varying hardness of the underside of the wearer's foot, and a
bottom surface comprising a hard shell covering at least a heel
portion of the bottom surface.
69. The human shoe sole of claim 68, characterized by one or more
of the following features: (a) wherein the hard shell includes side
walls that partially surround the heel portion of the insole; (b)
further comprising an asymmetric heel pad; (c) further comprising a
depression in the hard shell corresponding to the asymmetric heel
pad; (d) wherein the hard shell further comprises a frictional
surface for preventing slipping; (e) wherein the bottom surface
includes a plurality of grooves that are located beneath the
second, third, fourth and fifth metatarsal heads of the foot, and
and forward of the first metatarsal head of the foot; (f) including
a footbed, a lateral arch region, a medial arch region and a heel
region, wherein the footbed and the lateral arch region have a
first hardness value, the medial arch region has a second hardness
value that is softer than the first hardness value, and the heel
region has a third hardness value that is harder than the first and
second hardness values, wherein the footbed preferably includes a
forward region which includes a hollow or depression underlying the
first metatarsal head of the wearer; and (g) wherein the medial
arch region has a second hardness value that is at least 5 Shore C
points softer than the first hardness value, but not more than 10
Shore C points softer, and the heel region has a third hardness
value that is at least 10 Shore C points harder than the first
hardness values, but not more than 20 Shore C points harder.
70. A human shoe having a foot supporting upper surface including a
first region for supporting at least the first metatarsal head of
the foot, and a second region surrounding the first region for
supporting the remainder of the foot, at least in part, wherein the
first region provides less resistance to downward motion than the
second region, wherein the first region includes a hollow or
depressed area relative to the remainder of the first region having
a medial border portion and a lateral border portion, wherein the
depression has its lowest point skewed to the medial side of
center, whereby to promote eversion of the first metatarsal head as
the wearer moves from midstance through propulsive phase, wherein
the depression is formed in a location that is approximately 72.5%
of the length of the length of the insert, measured from the heel,
minus 10 mm.
71. The human shoe sole of claim 70, characterized by one or more
of the following features: (a) wherein the first region has a lower
durometer than the second region, wherein the first region
preferably has a Shore A hardness of 30-35; (b) wherein the first
region is formed of a plug of material surrounded by the second
region; (c) wherein the depressed area comprises an opening fouled
in and extending from the foot supporting upper surface; (d)
wherein the depression comprises a hollow formed below the foot
supporting upper surface; and (e) having a bottom surface that
includes a hard shell covering at least a heel portion of the
bottom surface.
72. A human shoe having a foot supporting upper surface, and a
bottom surface, the bottom surface includes a plurality of grooves
located beneath the second, third, fourth and fifth metatarsal
heads of the foot, and forward of the first metatarsal of the foot,
and an asymmetric heel pad having a depression located beneath the
heel.
73. The human shoe sole of claim 72, characterized by one or more
of the following features: (a) further including a plurality of
vent holes connecting the grooves to the upper surface for passing
moisture away from the upper surface; (b) wherein the foot
supporting upper surface includes side walls that partially
surround the heel portion of the wearer's foot; and (c) wherein the
depression beneath the heel is tear shaped.
74. An insole, or orthotic or sockliner for insertion into a human
shoe having a foot supporting upper surface having regions of
varying hardness that approximately match the regions of varying
hardness of the underside of the wearer's foot.
75. The insole, or orthotic or sockliner of claim 74, wherein the
foot supporting upper surface includes a footbed, a lateral arch
region, a medial arch region and a heel region, wherein the footbed
and the lateral arch region have a first hardness value, the medial
arch region has a second hardness value that is softer than the
first hardness value, and the heel region has a third hardness
value that is harder than the first and second hardness values.
76. The insole, or orthotic or sockliner of claim 73, characterized
by one or more of the following features: (a) wherein the lateral
arch region has a Shore C hardness value of 20 to 60; (b) wherein
the lateral arch region has a Shore C hardness of about 40; (c)
wherein the medial arch region has a Shore C hardness of about 15
to 55; (d) wherein the medial arch region has a Shore C hardness of
about 35; (e) wherein the heel region has a Shore C hardness of
about 30 to 70; (f) wherein the heel region has a Shore C hardness
of about 50; (g) wherein the footbed includes a forward region
which includes a hollow or depression underlying the first
metatarsal head of the wearer; and (h) wherein the medial arch
region has a second hardness value that is at least 5 Shore C
points softer than the first hardness value, but not more than 10
Shore C points softer, and the heel region has a third hardness
value that is at least 10 Shore C points harder than the first
hardness values, but not more than 20 Shore C points harder.
77. A human shoe having a foot supporting upper surface having
regions of varying hardness that approximately match the regions of
varying hardness of the underside of the wearer's foot.
78. The human shoe of claim 77, wherein the foot supporting upper
surface includes a footbed, a lateral arch region, a medial arch
region and a heel region, wherein the footbed and the lateral arch
region have a first hardness value, the medial arch region has a
second hardness value that is softer than the first hardness value,
and the heel region has a third hardness value that is harder than
the first and second hardness values.
79. The human shoe of claim 78, characterized by one or more of the
following features: (a) wherein the lateral arch region has a Shore
C hardness value of 20 to 60; (b) wherein the lateral arch region
has a Shore C hardness of about 40; (c) wherein the medial arch
region has a Shore C hardness of about 15 to 55; (d) wherein the
medial arch region has a Shore C hardness of about 35; (e) wherein
the heel region has a Shore C hardness of about 30 to 70; (f)
wherein the heel region has a Shore C hardness of about 50; (g)
wherein the upper surface includes a forward region which includes
a hollow or depression underlying the first metatarsal head of the
wearer; and (h) wherein the medial arch region has a second
hardness value that is at least 5 Shore C points softer than the
first hardness value, but not more than 10 Shore C points softer,
and the heel region has a third hardness value that is at least 10
Shore C points harder than the first hardness values, but not more
than 20 Shore C points harder.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of pending U.S.
application Ser. No. 12/534,741, filed Aug. 3, 2009. This
application also claims priority from U.S. Provisional Application
Ser. No. 61/360,412, filed Jun. 30, 2010, the contents of which are
incorporated herein in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to footwear and, more
particularly to insoles for footwear having features that improve
the comfort for the wearer during standing, walking and
running.
BACKGROUND OF THE INVENTION
[0003] Footwear has undergone significant evolutionary advances in
technology, particularly since the development of the
electrodynogram which has permitted researchers to measure dynamic
forces and to better understand biomechanical action of a human
foot within a shoe while the wearer is walking or running. Using
this tool, many researchers have made technological advances
directed towards the mid-sole of a shoe. Since the mid-sole
functions primarily as a suspension system of the sole of the foot,
and often provides both protective cushioning and a stable platform
for the wearer's foot, many conventional technologies have focused
on cushioning the impact associated with foot strike by varying the
spring coefficients in the mid-sole to dispense shock.
[0004] In my earlier U.S. Pat. No. 4,597,195 I describe a discovery
of a then previously misunderstood phenomena, functional hallux
limitus, that is believed to affect a majority of the population.
To treat functional hallux limitus I created an improved shoe sole
design which permits the first metatarsal to better achieve
plantarflex relative to the great toe and remaining metatarsal
heads. As explained in my aforesaid '195 patent, plantarflex allows
for the extension of the human great toe during human gate cycle in
an efficient fashion. More particularly in accordance with my prior
'195 patent, I created a human shoe sole having an area of reduced
support underlying substantially only the location of the first
metatarsal head of the wearer's foot. As described in my '195
patent, providing an area of reduced support substantially only
under the head of the first metatarsal encourages eversion and
plantarflexion of the first metatarsal head as weight shifts from
the heel to the first ray. Thus the normal functioning of the foot
for plantarflexion and supination is encouraged with beneficial
results for improved walking comfort and shock absorption on
subsequent heel contact. Following my discovery millions of pairs
of shoes have been manufactured with foot beds having an area of
reduced support underlying substantially only the location of the
first metatarsal head of the wearer's foot, to encourage
plantarflexion of the first metatarsal head.
SUMMARY OF THE INVENTION
[0005] In one aspect, the present invention provides an improved
insole which incorporates an area of reduced support which includes
an asymmetrically shaped depression under the first metatarsal
head, fashioned with its lowest point skewed to the medial side of
center. This unique shape further encourages the first metatarsal
head into eversion as the wearer moves from midstance to propulsive
phase.
[0006] As used herein the term "sole" and "inner sole" are used
interchangeably. Moreover, a "sole" or "insole" may be an element
built into or forming an integral element of a footwear product
such as an insole board, or as a separate element, including, e.g.
a sock liner or removable insole, an after-market insole device, or
a custom or prefabricated foot orthotic, which may be inserted into
a footwear product post-manufacture. The element also may be cut
into or formed in the foot supporting surface of a shoe.
[0007] In another aspect, the present invention provides an insole
or orthotic for insertion into a human shoe having a foot
supporting upper surface having regions of varying hardness that
approximately match the regions of varying hardness of the
underside of the wearer's foot, and a bottom surface comprising a
hard shell covering at least a heel portion of the bottom surface.
The hard shell may include side walls that partially surround the
heel portion of the insole. The insole or orthotic may also include
an asymmetric heel pad which corresponds to the shape of the
calcaneus. The hard shell includes a depression corresponding to
the asymmetric heel pad, so that the upper surface is apparently
undisturbed. The bottom surface preferably also includes a
plurality of grooves that are located under the second, third,
fourth and fifth metatarsal heads of the foot which grooves serve
to increase flexibility of the insole.
[0008] Yet another aspect of the present invention provides an
insole or orthotic for insertion into a human shoe having a foot
supporting upper surface including a first region for supporting at
least the first metatarsal head of the foot, and a second region
surrounding the first region for supporting the remainder of the
foot, at least in part, wherein the first region provides less
resistance to downward motion than the second region, wherein the
depression has its lowest point skewed to the medial side of
center, whereby to promote eversion of the first metatarsal head as
the wearer moves from midstance through propulsive phase. The
depression is formed in a location that is approximately 72.5% of
the length of the length of the insert, measured from the heel,
minus 10 mm.
[0009] Still yet another aspect of the present invention provides
an insole for insertion into a human shoe having a foot supporting
upper surface, and a bottom surface comprising a hard shell
covering at least a heel portion of the bottom surface. The bottom
surface includes a plurality of grooves that are located in the
insole or orthotic beneath the second, third, fourth and fifth
metatarsal heads of the foot, forward of the first metatarsal head,
which grooves serve to increase flexibility of the insole or
othotic. The invention also includes a plurality of vent holes
connecting the grooves to the upper surface for passing moisture
away from the upper surface.
[0010] Finally, the present invention provides further improvements
in insoles for footwear which can be used alone or in combination
with a depression under the metatarsal as described in my earlier
'195 patent and as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Further features and advantages of the present invention
will be seen from the following detailed description, taking in
conjunction with the accompanying drawings, wherein:
[0012] FIG. 1 is a top plan view of a sole incorporating an insert
according to a first embodiment of my present invention for the
right foot;
[0013] FIG. 1A is a top plan view showing details of an insert
element, with contour lines taken at 0.3 cm superimposed thereon,
according to the first embodiment;
[0014] FIGS. 2A-2C are cross-sectional views taken along lines
IIA-IIC of FIG. 1;
[0015] FIG. 2D is a cross-sectional view taken along lines HD of
FIG. 1;
[0016] FIG. 3 is a top plan view, and FIG. 4 a transparent
perspective view, with contour lines taken at 0.3 cm superimposed
thereon, showing details of portions of a second embodiment of the
insert element of my invention;
[0017] FIG. 5 is a cross-sectional view showing a third embodiment
of my invention;
[0018] FIG. 6 is a perspective view of a sole according to a fourth
embodiment of my invention;
[0019] FIGS. 7A and 7B are top and bottom, respectively, of an
insert element constructed in accordance with a fifth embodiment of
my invention;
[0020] FIGS. 8A and 8B are cross-sectional views taken along lines
VIIIA and VIIIB of FIGS. 7A and 7B;
[0021] FIGS. 9A and 9B are top and side views of a shell in
accordance with the embodiment shown in FIGS. 7A and 7B; and
[0022] FIGS. 10A and 10B are cross-sectional views taken along
lines XA and XB of FIGS. 9A and 9B.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to FIGS. 1, 1A and 2A-D of the drawings, footwear
made in accordance with the present invention includes foot
supporting surfaces, i.e., a sole, designated reference numeral 10,
having a heel section 12, an arch section 14, a forefoot section 16
and a toe section 18, corresponding to parts of a wearer's foot. In
use, the heel section 12 underlies the heel of the wearer's foot
and includes medial and lateral regions designated 20, 22,
respectively corresponding to the inner and outer sides of the
foot. Likewise, the arch section 14 which is forward the heel
section 12, underlies the arch of the wearer's foot and also
includes medial and lateral regions 24, 26, respectively. The
forefoot section 16 is forward the arch section 14 and includes the
so-called ball of the foot which includes the first, second, third,
fourth and fifth metatarsals indicated in phantom at M1-M5. The
ball of the foot also includes first, second, third, fourth and
fifth metatarsal heads (N1-N5) associated with the respective
first, second, third, fourth and fifth metatarsal heads, and first,
second, third, fourth and fifth proximal phalanges (PP1-PP5)
forward of the respective first, second, third, fourth and fifth
metatarsal heads, and associated metatarsal first, second, third,
fourth and fifth metatarsal phalangeal joints (not labeled) between
the associated metatarsal heads and proximal phalageals. The
forefoot section 16 is divided into first and second regions
designated 28 and 30, respectively. The first region 28 is adapted
to underlie the first, second, third, and fourth metatarsal heads
and optionally the fifth metatarsal head, in part, while the second
region 30 is adapted to underlie the proximal phalanges (PP1-PP5),
at least in part. The toe section 18 of the sole is spaced forward
of the forefoot section 16 and underlies at least the middle
phalanges MP2-MP5 and distal phalanges DP1-DP5 of the toe of the
wearer's foot.
[0024] The sole 10 is formed so that an area of reduced support or
reduced resistance to downward loading or movement is located in
the first region 28 of the forefoot section 16. The first region 28
is formed of a resiliently deformable material that offers less
resistance to downward movement than the region surrounding the
first region, i.e. the second region 30, and also the toe section
region 18. Region 28 may be formed of a material having a lower
durometer than the surrounding regions 30 and 18. Preferably,
region 28 will have a Shore A hardness in the range of 30-35, which
closely matches the hardness of the fat pad of a typical human
foot. Alternatively, region 28 may be made thinner so as to at
least in part fall below the surface of the second region 30 and
toe section 18. Region 28 may be formed as a separate element, e.g.
a plug or insert 40 cut or built into the sole 10, or as a recess
formed in the top or bottom surface of the sole, e.g. by molding or
by machining. Region 28 may be covered by a flexible liner (not
shown).
[0025] Also, a region within region 28, underlying substantially
only the first metatarsal head of the wearer includes a hollow or
depression 42, relative to the remainder of region 28, of
asymmetric shape, with the lowest point of the hollow or depression
skewed to the medial side of center. That is to say, as seen
particularly in FIG. 1A, the hollow or depression 42 has a
shallower slope on its lateral side.
[0026] In practice, depression 42 is round or nearly round in plan,
and the corresponding medial and lateral walls 44 and 46 are also
somewhat rounded or curved. Accordingly, as used herein, "slope" is
an imaginary line or cord running between the top edge of the side
wall and a point where the side wall morphs into the bottom of the
depression. This is best seen by phantom line 43 (FIG. 4) which is
an imaginary cross-sectional line through the midpoint of insert
40. This unique geometry has the effect of rotating the first
metatarsal head of the wearer into eversion as the wearer moves
from midstance to propulsive phase.
[0027] In dimensions, the hollow depression 42 should be large
enough in plan to accommodate the first metatarsal head, at least
in part. In a typical embodiment, depression 42 is substantially
circular in plan, preferably having a diameter of about 2.54 cm. to
about 3.81 cm., depending on foot size. The depression also may be
oval, egg-shaped, or elongated in plan, and should have a nominal
depth preferably in the range of about 2-3 mm measured from the top
edge of the side walls to the lowest point of the depression.
Despite this relatively small amount, this has a profound effect of
rotating the first metatarsal head into eversion as the wearer
moves from midstance to propulsive phase. In an alternative
embodiment, the depression 42A is somewhat elongated and slightly
wider at its toward end, e.g. as shown in FIG. 3-4.
[0028] The soles described above may be used with street and sport
footwear including sandals. As noted above, the soles may be
incorporated into an insole board at the time of manufacture,
formed as a sock liner or as an aftermarket insole device or a
custom or prefabricated (over-the-counter) orthotic for placing
into a shoe by the wearer.
[0029] FIG. 6 is an illustration of a shoe sole 110, in accordance
with one embodiment of the present disclosure. The shoe sole 110
includes a composite insole having a footbed 112, a lateral arch
region 114, a medial arch region 116, and a heel region 118. The
footbed 112 and the lateral arch region 114 have a first hardness
value. The medial arch region 116 has a second hardness value that
is softer than the first hardness value. The heel region 118 has a
third hardness value that is harder than the first hardness
value.
[0030] In use, the heel region 118 underlies the heel of the
wearer's foot. Likewise, the lateral arch region 114 and the medial
arch region 116 underlie the arch of the wearer's foot. The footbed
112 extends from the central space between the lateral arch region
114 and the medial arch region 116 to the fore of the shoe sole
110, beneath the ball of the wearer's foot, including the first,
second, third, fourth, and fifth metatarsals. Varying durometers of
the shoe sole 110 are selected to approximately match the regions
of varying hardness of the underside of the wearer's foot. While
foot shapes and size vary from person to person, anthropometric
studies show that the hardness of the "fat pad" of the bottom of
the average human foot does not vary significantly. Accordingly, we
have determined that footwear may be made significantly more
comfortable to the average user, and bio-mechanical efficiency
improved by varying the hardness of the insole to approximately
match the regions of varying hardness of the underside of the
wearer's foot. In essence, in the context of the present invention,
applicants mechanically impedance match the insole to the underside
of the foot so that the amount the insole moves for given force is
essentially the same as the movement of the padding of the
underside of the foot. In this way, the insole is a natural
extension of the padding of the underside of the foot. For example,
the first hardness value may be approximately 20 to 60 Shore C,
preferably about 40 Shore C, the second hardness value may be
approximately 15 to 55 Shore C, preferably about 35 Shore C, and
the third hardness value may be approximately 30 to 70 Shore C,
preferably about 50 Shore C, where Shore C is a durometer scale
recognized by the American Society for Testing and Materials. Under
Shore A, another durometer scale recognized by the American Society
for Testing and Materials, those preferred values are approximately
20 Shore A, 15 Shore A, and 30 Shore A, respectively.
[0031] While the footbed 112 and the lateral arch region 114 are
described as having the first hardness value, these two regions may
have slightly different hardness values without departing from the
scope of the present disclosure. Rather these regions are described
together based upon having approximately similar hardness values
relative to the heel region 118 and the medial arch region 116.
[0032] In another embodiment of the invention, the footbed 112 may
also have a depression or hollow 120 located approximately beneath
the location of the first metatarsal head of a user's foot, i.e. in
accordance with the teachings of my aforesaid U.S. Pat. No.
4,597,195 or my aforesaid co-pending U.S. application Ser. No.
12/534,741, and as described above with reference to FIGS. 1-5. As
described in my aforesaid '741 application, and above, the hollow
or depression 120 promotes eversion of the first metatarsal head as
the wearer moves from midstance through propulsive phase. This
hollow or depression 120 should have the same approximate hardness
as footbed 112 and the lateral arch region 114, though differences
may be expected depending on the method of production.
[0033] FIGS. 7A-10B depict a further embodiment of the invention
which combines some of the features discussed above with additional
improvements. This embodiment features an insert 210 having a
depression 220 that is located and sized to accommodate most users.
By using a formula to predict the proper location of the
depression, the inserts can be produced to predictably accommodate
approximately 95% of users. The optimal location for the
depression, as measured from the back of the heel portion 218, is
72.5% of the length of the foot (or the length of a typical foot
for a particular shoe size, as the case may be), minus 10 mm based
on anthropometry studies conducted by the United States Army Natick
Research, Development and Engineering Center, Technical Report
Natick/TR-92/028, entitled "Anthropometry of the Foot and Lower Leg
of U.S. Army Soldiers: Fort Jackson, SC-1985", by Kenneth R.
Parham, Claire C. Gordon, and Carolyn K. Bensel, Final Report,
dated September 1992. The depression itself is appropriately sized
according to any of the methods described above or in the
aforementioned, commonly owned, patent applications.
[0034] As with the examples described above, the insert may be
constructed with a multidurometer top surface intended to match the
hardness of various regions of the typical adult foot. In this
example, lateral arch region 214 and the footbed region 212 are
constructed with a Shore C hardness of 40, the medial arch region
216 is constructed with a Shore C hardness of 35, and the heel
region 218 is constructed with a Shore C hardness of 50. These
hardness levels are typical, but may vary, for example, by .+-.5 on
the Shore C hardness scale. Another advantageous feature of this
embodiment is shell 230, which is included to provide structural
support and to reduce the deformation of the geometry of the
footbed under load. The shell 230 typically is formed of a
material, such as a hard plastic, that meets this criteria without
significantly increasing the cost of manufacturing the insert. In
the example depicted by the figures, the shell is located on the
bottom of the insert, and covers roughly half of the bottom of the
insert, including the heel. Shell 230 can be seen as a separate
component in FIGS. 9A-10B. Alternatively, the insert may be
constructed with a shell that covers as much as the entire bottom
of the insert. In any event, the shell should always be configured
to cover the area of the heel. The hard shell may also comprise
sidewalls 232, which surround the heel portion of the insert to aid
the alignment of the insert with the heel and to provide some
lateral support.
[0035] FIGS. 7B and 8B show an additional feature of the present
embodiment, wherein the insert includes an asymmetric portion 236
in the insert beneath the heel. This feature more appropriately
matches the irregular surface of the bottom of the calcaneus, thus
improving comfort. The shell includes a corresponding depression,
heel depression 234, which further provides some plantar relief
without disturbing the top surface geometry. Depression 234 can
also be seen independent of the asymmetric heel pad in FIGS. 9A,
10A and 10B. Upward projecting solutions, in contrast, do not
provide significant relief to the irregular geometry of the
calcaneus.
[0036] Further, the example shown includes a frictional surface
238, which can be located surrounding the asymmetric portion 236 of
the insert, which is shown protruding through the heel depression
in the shell 230. The frictional surface provides a non-slip
surface so that the insert stays securely in place. Frictional
surface 238 may be in the form of a ridge 244, as shown in FIG. 8B.
Alternatively, the surface may be a deformable material with a high
coefficient of friction.
[0037] This embodiment also includes a series of grooves 240 on the
bottom of the insert. These grooves are sized and located to
increase the flexibility of the insert where appropriate. The
grooves may provide access to a plurality of vent holes 244, which
are arranged to allow moisture to pass through the insert, thereby
avoiding further discomfort. However, the grooves should end
forward of the first metatarsal head, leaving flat portion 242,
thereby advantageously reducing the flexibility of the insole under
the big toe.
[0038] The various regions of the device, according to any of the
embodiments described above, may be manufactured unitarily, may be
co-extruded, bonded together, adhesively joined, chemically joined,
mechanically joined, or unified in any manner known to those having
ordinary skill in the art. The shoe sole device may be used with
men's, women's and children's street and sport footwear, including
sandals. The shoe sole may be incorporated into an insole board at
the time of manufacture, formed as a sock liner, or as an
aftermarket insole device or a custom or prefabricated
over-the-counter orthotic for placing into a shoe by the wearer. If
formed within a sock liner, insole board, or other similar
encompassing product, the various regions of the shoe sole 10 may
not be joined to each other, but may simply be held in place by the
encompassing product.
[0039] Various changes can be made in the above construction
without departing from the scope of the invention. For example, an
asymmetrically shaped hollow having tapered side walls skewed to
the medial side of center may be formed extending downwardly from
the bottom of an insole board or sock liner of a shoe, and
underlying substantially only the first metatarsal head. It is
intended therefore that matter contained in the above description
or shown in the accompanying drawings shall be interpreted as an
illustrative and not in a limiting sense.
* * * * *