U.S. patent application number 14/363045 was filed with the patent office on 2014-11-20 for footwear/insole for footwear.
This patent application is currently assigned to FootJacks Ltd. The applicant listed for this patent is FOOTJACKS LTD.. Invention is credited to Mark Stern.
Application Number | 20140338220 14/363045 |
Document ID | / |
Family ID | 45541432 |
Filed Date | 2014-11-20 |
United States Patent
Application |
20140338220 |
Kind Code |
A1 |
Stern; Mark |
November 20, 2014 |
FOOTWEAR/INSOLE FOR FOOTWEAR
Abstract
A footbed for supporting a person's foot is formed with one or
more voids which removes support beneath either at least part of
the heel which is lateral to the midline of the heel and which does
not extend medially of the midline, or beneath the medial process
of the tuber calcanei, or a combination of the two. Such voids
stabilise those parts of the heel which functionally form an
abutment to support the medial and lateral longitudinal arches of
the foot, in order to prevent pronation.
Inventors: |
Stern; Mark; (Hertfordshire,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FOOTJACKS LTD. |
Hertfordshire |
|
GB |
|
|
Assignee: |
FootJacks Ltd
Hertfordshire
GB
|
Family ID: |
45541432 |
Appl. No.: |
14/363045 |
Filed: |
December 10, 2012 |
PCT Filed: |
December 10, 2012 |
PCT NO: |
PCT/GB2012/053073 |
371 Date: |
June 5, 2014 |
Current U.S.
Class: |
36/43 |
Current CPC
Class: |
A43B 7/144 20130101;
A43B 7/143 20130101; A41B 11/008 20130101; A43B 7/145 20130101;
A43B 7/1405 20130101; A43B 13/14 20130101; A43B 7/1475 20130101;
A43B 7/1435 20130101; A43B 17/00 20130101; A43B 7/1425 20130101;
A43B 7/142 20130101 |
Class at
Publication: |
36/43 |
International
Class: |
A43B 13/14 20060101
A43B013/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2011 |
GB |
1121142.2 |
Mar 9, 2012 |
GB |
1204153.9 |
May 30, 2012 |
GB |
1209615.2 |
Dec 10, 2012 |
WO |
PCTGB2012053073 |
Claims
1. A footbed for supporting a person's foot, wherein the footbed is
formed with one of more voids which remove support beneath either:
at least part of the heel which is lateral to the midline of the
heel and which does not extend medially of the midline, and with no
other void in the part of the heel medial to the midline; or
beneath the medial process of the tuber calcanei; or beneath both
the lateral part of the heel and the medial process of the tuber
calcanei, thereby to stabilise those parts of the heel which
functionally form abutments in the calcaneus to support the medial
and lateral longitudinal arches of the foot.
2. A footbed as claimed in claim 1, wherein the footbed is formed
with avoid (V1) to remove support from the heel beneath at least
part of the anterio-medial calcaneal ground contact which is
lateral to the midline of the heel and does not extend medially of
the midline,
3. A footbed as claimed in claim 1, wherein the footbed is formed
with a void (V2) so as to remove support from the heel beneath the
lateral process of the tuber calcanei.
4. A footbed as claimed in claim 1, wherein the footbed is formed
with a void (V4) so as to remove support from the heel beneath the
anterio-lateral ground contact of the calcaneous.
5. A footbed as claimed in claim 1, wherein the footbed is formed
with at least one void (V5-V9) so as to remove support from the
forefoot beneath the heads of one, a combination or all of the
metatarsals.
6. A footbed as claimed in claim 1, wherein the footbed is formed
with a void (V10) so as to remove support from the forefoot beneath
the distal phalanx of the hallux.
7. A footbed as claimed in claim 1, further comprising a raised
mound in the medial arch area of the midfoot and at least one void
anywhere in the arch area of the midfoot.
8. A footbed as claimed in claim 1, wherein the footbed is
substantially flat and formed with at least one void in the medial
longitudinal arch area or the lateral longitudinal arch area of the
midfoot,
9. The footbed as claimed in claim 1, wherein the footbed is
arranged to support the foot with a downward slope from heel to
forefoot at an angle of less than 20 degrees.
10. A footbed as claimed in claim 1, wherein the footbed is
arranged to support the foot with a downward slope from heel to
forefoot of or greater than 20 degrees and further comprises a void
beneath the anterio-medial calcaneal ground contact which extends
both medially and laterally of the midline.
11. A footbed for supporting a person's foot, wherein the footbed
includes a forefoot area receiving the parts of the foot beneath at
least the heads of the first and fifth metatarsals, such that in
use the heads of the first and fifth metatarsals are raised
relative to the anterior-medial calcaneal ground contact of the
heel by at least 0.5 cm, and the toes are level with or lower than
the heads of the first and fifth metatarsals.
12. A footbed as claimed in claim 11, wherein the footbed further
comprises a toe area distal to the forefoot area for receiving the
toes, and the toe area and forefoot area are generally flat and
level with each other.
13. A footbed as claimed in claim 11, wherein the footbed further
comprises a toe area distal to the forefoot area for receiving the
toes, and a heel area for receiving at least part of the heel, and
the toe area and heel area are generally flat and level with each
other, and the forefoot area is raised relative to the heel
area.
14. A footbed as claimed in claim 11, further comprising a midfoot
area between the forefoot area and the heel area, wherein part of
the midfoot area beneath the medial arch of a foot comprises a
raised mound.
15. A footbed as claimed in claim 1, wherein the footbed comprises
a plurality of separate bodies.
16. A footbed as claimed in claim 15, wherein the separate bodies
are releasably connectable to each other.
17. A footbed as claimed in claim 1, wherein the footbed is
integral with an item of footwear.
18. A footbed as claimed in claim 17, wherein the item of footwear
comprises a flexible sock or stocking.
19. A footbed as claimed in claim 1, wherein the footbed is
releasably attachable to the sole of a foot.
20. A footbed as claimed in claim 1, wherein the footbed comprises
an insole insertable into pre-existing footwear.
21. A footbed as claimed in claim 1, wherein the footbed comprises
one or more optionally removal sections in order to create one or
more voids
22. A footbed as claimed in claim 1, wherein the or each void
comprises one of: a hole through the footbed and a depression in
the footbed.
23. A footbed as claimed in claim 22, further comprising a thin,
flexible layer which extends over the or each void and is
deformable into the or each void under the weight of a person
standing on the footbed.
Description
[0001] The present invention relates to footwear for treating
pronation. The invention may comprise an item such as an insole
which is insertable into pre-existing footwear or it may be
embodied as an integral part of an item of footwear itself.
[0002] Pronation is a common foot problem. It occurs particularly
in people with flat feel (Pes Planus). Pronation tends to occur in
such people as they walk and refers to the condition where parts of
the hind foot, mid foot and forefoot tend to lean medially
(inwards) and the arch of the foot flattens and tips over medially.
When this happens the soft tissues become stretched and the joint
surfaces of the bones in the foot are placed at unnatural angles to
one another. The tipping over of the arch leads to a decrease in
the support of the structures supported by that foot.
[0003] Various insoles for treating over pronation are known. Some
of these include a built up or raised area beneath the arch of the
foot to contact and push upwardly on the arch. However, many people
still find such insoles ineffective in treating the problem.
[0004] Insoles are also known which have parts of the arch area
removed. However, this has been found to be ineffective in stopping
pronation when a person walks and each step begins with a heel
strike.
[0005] The present invention provides a footbed for supporting a
person's foot, wherein the footbed is formed with one or more voids
which remove support beneath either: at least part of the heel
which is lateral to the midline of the heel and which does not
extend medially of the midline, and with no other void in the part
of the heel medial to the midline; or beneath the medial process of
the tuber calcanei; or beneath both the lateral part of the heel
and the medial process of the tuber calcanei thereby to stabilise
those parts of the heel which functionally form abutments in the
calcaneus to support the medial and lateral longitudinal arches of
the foot.
[0006] In one embodiment, the footbed is formed with a void in the
heel region, an area referred to herein as V1, positioned beneath
the lateral aspect of the anterio-medial ground contact of the
calcaneus, being lateral to a midline of the foot and aligned
substantially with the 4.sup.th toe. Most text books on the subject
provide that the anterior aspect of the calcaneus is not in ground
contact. The writer has found, however, that this ground contact
does occur in people with Pes Planus, and in conjunction with
others, allows pronation to occur. The weight of the body reaches
this point before the anterior arch abutments contact the ground.
At this point the arches are formed loosely with flexibility
between the joints. Once the posterior abutments at the Tuber
Calcanei and the anterior abutments are in ground contact with the
weight of the body acting through the arches, ground reaction
forces `firm up` the arches.
[0007] With pronation, the anterio-medial calcaneal ground contact
functionally acts as an abutment to both medial and lateral long
plantar arches. Instability at this contact point allows the arches
to `tip over` provided either the anterior or posterior medial
calcaneal abutments are allowed to roll medially. This can be
prevented in a flat shoe, with a void in the lateral heel which
tips and holds the anterio-medial calcaneal contact laterally or
with a void, beneath the medial process of the tuber calcanei
(referred to herein as area V3)or a combination of voids in these
areas.
[0008] A void directly beneath the lateral aspect of the
anterio-medial calcaneal ground contact (V1) serves to prevent
pronation at the talocalcaneonavicular (TCN) joint complex which
occurs with a heel strike when the weight of the body reaches the
ground contact point.
[0009] In alternative embodiments, the body may be formed with
voids in those parts of the lateral heel which are not within the
region V1 described above and which indirectly prevent medial
rolling at the anterio-medial calcaneal ground contact. For
example, the body may be formed with voids under the lateral
process of the tuber calcanei (V2), and under the anterio-lateral
calcaneal ground contact (V4) occurring in people with collapsed
arches.
[0010] In addition to the aforementioned, voids may be beneath any,
a combination, or all of the metatarsal joints (V5-V9) and/or under
the tuberosity beneath the distal phalanx of the hallux (V10).
[0011] In a further embodiment, the footbed may also include a
raised mound in the medial arch area of the midfoot and at least
one void anywhere in the arch area of the midfoot. Alternatively,
the footbed may be substantially flat and have at least one void
formed in the medial longitudinal arch area, or in the lateral
longitudinal arch area of the midfoot (i.e. regions 14b and 14c as
described further below).
[0012] The voids should preferably be separate and beneath each
individual area described above as these increase the resistance to
pronation.
[0013] The upper surface of the footbed may be arranged to support
the foot with a slope downwardly from the heel region to the toe
region at an angle of less than 20.degree., for flat or low-heeled
footwear.
[0014] In another embodiment, for higher-heeled footwear, the
footbed is arranged to support the foot so that it slopes down from
the heel region to the toe region at an angle of or greater than
20.degree.. At this angle there is no pronation permitted by the
TCN joint complex through the mid foot. However, inversion and
eversion of the foot occurs as a consequence of rolling medially or
laterally across the metatarsal and phalangeal ground contacts and
at the heel contact. To prevent this, the footbed may further
comprise a void beneath the anterio-medial ground contact which
extends both medially and laterally of the midline.
[0015] The or each void in the footbed may comprise a hole through
the footbed or a depression in the footbed. Further, a thin,
flexible layer may extend over the or each void to cover the void,
but providing no support to the foot. The layer must be deformable
into the or each void under the weight of a person standing on the
footbed.
[0016] Preferably, the or each void has a minimum size of
approximately 0.6 cm.sup.2 to 1 cm.sup.2, allowing the tissues in
the sole of the foot to sink into the void.
[0017] The footbed may comprise a body made up of a plurality of
separate bodies, which may be releasably connectable to each other.
The footbed may be formed integrally with an item of footwear, and
the item of footwear may comprise a flexible sock or stocking.
Alternatively, the footbed may be releasably attachable to the sole
of a foot. In a further alternative, the footbed may comprise an
insole insertable into pre-existing footwear.
[0018] The footbed may comprise one or more optionally removable
sections in order to create one or more voids.
[0019] The footbed may comprise a very thin layer of particulate
material at least beneath those points which directly or indirectly
stabilise the abutments to the medial and longitudinal arches of
the foot. The layer should be thin enough so that the particulates
do not compact into a hard surface. In this way, they create voids
which act at the relevant points.
[0020] In another aspect of the invention there is provided a
footbed for supporting a person's foot, wherein the footbed
comprises a forefoot area receiving the parts of the foot beneath
at least the heads of the first and fifth metatarsals, such that in
use the heads of the first and fifth metatarsals are raised
relative to the anterio-medial calcaneal ground contact of the heel
by at least 0.5 cm, and the toes are level with or lower than the
heads of the first and fifth metatarsals.
[0021] The footbed may further comprise a toe area distal to the
forefoot area for receiving the toes, wherein the toe area and
forefoot area are generally flat and level with each other.
[0022] Alternatively, the footbed may further comprise a toe area
distal to the forefoot area for receiving the toes, and a heel area
for receiving at least part of the heel, wherein the toe area and
heel area are generally flat and level with each other, and the
forefoot area is raised relative to the heel area.
[0023] The footbed may also comprise a midfoot area between the
forefoot area and the heel area, wherein part of the midfoot area
beneath the medial arch of the foot comprises a raised mound.
[0024] The invention will now be described in more detail, by way
of example only, with reference to the accompanying drawings in
which:
[0025] FIG. 1a is a schematic medial view of the plantar arch of a
foot;
[0026] FIG. 1b is a diagram illustrating the main regions of the
sole of a foot;
[0027] FIG. 2 illustrates a footbed in accordance with a first
embodiment of the present invention;
[0028] FIG. 3 illustrates a footbed in accordance with a second
embodiment of the present invention;
[0029] FIG. 4 illustrates a footbed in accordance with a third
embodiment of the present invention;
[0030] FIG. 5 illustrates a footbed in accordance with the present
invention and formed of separate parts (with the voids omitted for
clarity); and
[0031] FIG. 6 illustrates a sock incorporating a footbed in
accordance with the present invention (with the voids omitted for
clarity).
[0032] FIGS. 7a-c illustrate cross sections of a footbed in
accordance with further embodiments of the invention.
[0033] The human foot is a complicated structure which has many
functions. One function is to support the weight of the body so
that all structures above the foot are maintained in their correct
positions during movement and in the standing position.
[0034] The weight of the body is supported on two longitudinal
arches in the foot, the medial and longitudinal plantar arches.
These arches are bony in structure and maintained by ligamentous
and muscular factors. These arches have abutments to support the
arches.
[0035] FIG. 1a shows a schematic medial view of a foot, with some
of the bones removed for clarity. The foot should naturally assume
an arched form as shown, with the weight of the body represented by
arrow F acting downwardly and then being transmitted in directions
F1 and F2 to the correct ground contact points, which act as
abutments to the arches. The correct posterior abutments to the
arches are the medial and lateral processes of the tuber calcanei.
However, in a person whose foot tends to pronate, the arch tends to
collapse in the direction of arrows P1 and P2, flattening and
reducing the size of the arch. Thus, with flat feet (Pes Planus), a
functional abutment occurs when there is an anterio-medial and
anterio-lateral calcaneal ground contact.
[0036] These functional abutments have the effect of shortening the
medial long plantar arch. It is the anterio-medial calcaneal ground
contact which must be stabilised to prevent pronation and this can
be done directly or indirectly.
[0037] Thus the abutments of the medial and lateral longitudinal
arches are found in the calcaneus and under the heads of the
metatarsals, although the 1.sup.st and 5.sup.th metatarsal heads
bear most of the weight passing through the anterior aspect of the
arches until the weight of the body moves into the mid foot.
[0038] Direct removal of support from beneath the lateral aspect of
the anterio-medial ground contact forming a functional abutment
stabilises the rear abutment at this contact and allows the
longitudinal arches of the foot to firm up and function correctly
during a heel strike. Indirectly stabilising the anterio-medial
ground contact with a void at V3 or in the lateral heel other than
in area V1 stabilises the heel until the heel starts to lift at the
position the void is placed so that it ceases to "act". A void in
area V3 stabilises the midfoot whilst voids in the lateral heel
area other than area V1 only stabilise the midfoot in conjuction
with one or more voids in the midfoot.
[0039] FIG. 1b illustrates schematically the sole of a foot 10
which has been divided up into various regions as defined below. In
the following description the terms anterior and posterior are used
to denote forward and backward directions as shown by the arrows in
FIG. 1b, and terms medial and lateral are used to denote inner and
outer directions, either side of the foot's midline, M, as shown by
the arrows in FIG. 1b.
[0040] For the purpose of describing the present invention, the
foot in a person with Pes Planus is considered as comprising the
following general regions: the heel 12, the arch 14, the heads of
the metatarsal joints 16 and the toes 18. The various parts of the
foot can also be described as the fore-foot, consisting of the
metatarsal joint region 16 and the toes 16, the mid-foot consisting
of the arch 14, and the hind-foot consisting of the heel region 12.
Although the heel normally functions as part of the bony arch of
the foot, with hind foot pronation the anterio-medial ground
contact of the calcaneus forms a functional abutment and the arch
is confined to the mid foot.
[0041] The arch 14 may be considered to consist of a medial strip
14a at the extreme medial edge of the arch 14, a medial
longitudinal arch region 14b, a lateral longitudinal arch region
14c and a lateral strip 14d at the extreme lateral edge. In the
area of the arch 14, the notional dividing line between the medial
and lateral longitudinal arch regions is somewhat diagonal as
illustrated, rather than strictly following the overall midline M
of the foot.
[0042] For the purpose of describing the present invention, the
foot is shown with those areas (V1-V10) in the heel, the midfoot
and the forefoot which stabilise the medial and lateral
longitudinal arches of the foot. The illustration is schematic and
the precise locations will depend on the anatomy of an
individual.
[0043] V1 represents the area which stabilizes that part of the
anterio-medial calcaneal ground contact which prevents pronation in
the heel and through the midfoot. It is the part of the ground
contact from the midline of the foot and lateral to the midline,
substantially aligned with the 4.sup.th toe as shown in the
diagram. The area V1 is only lateral to the midline and must not
extend across the midline into the medial side of the foot or have
a balancing void in the medial aspect of the heel other than at V3
(defined below).
[0044] V2 is under the lateral process of the tuber calcanei.
[0045] V3 is under the medial process of the tuber calcanei.
[0046] V4 is under the anterio-lateral ground contact of the
calcaneus.
[0047] V5 is under the sesamoid bones under the head of the
1.sup.st metatarsal.
[0048] V6 is under the head of the 5.sup.th metatarsal.
[0049] V7, V8 and V9 are under the heads of the 2.sup.nd, 3.sup.rd
and 4.sup.th metatarsals.
[0050] V10 is under the distal phalanx of the hallux.
[0051] What follows refers to the situation when the angle of the
footbed, i.e. a surface on which the foot rests from hind foot to
forefoot, is below approximately 20 degrees, when the foot is in
the easy standing position. Below this angle the TCN joint complex
is free to allow pronation through the hind and mid foot.
Obviously, even with such a footbed, a slope of greater than 20
degrees occurs at push off as the heel is lifted off the
ground.
[0052] The inventor has discovered that, in people whose feet
pronate, the front of the calcaneus collapses anteriorly giving
rise to two anterior calcaneal ground contacts. The more medial
contact is roughly in line with the 3rd and 4th toes extending into
the lateral half of the heel. The more lateral ground contact is on
the inferior surface of the anterio-lateral calcaneal process. It
is the anterio-medial calcaneal ground contact which is largely
responsible for pronation through the heel and needs to be
stabilised.
[0053] If a void is at V3 and not V1, then voids at V2 and V4
prevent small amounts of pronation through the lateral heel. A void
at V1 itself will prevent pronation through the hindfoot with a
heel strike and through the midfoot.
[0054] As mentioned, the front ground supports in the easy standing
position are mainly on the tuberosities under the heads of the
1.sup.st and 5.sup.th metatarsals (V5 and V6) although the other
metatarsal heads bear more weight once the weight of the body moves
into the anterior mid foot. They represent the anterior abutments
for the medial and lateral long plantar arches. The two sesamoid
bones will bear the weight at the 1.sup.st metatarsal head support.
The 1.sup.st and 5.sup.th ground supports should contact the ground
together.
[0055] The inventor has discovered that removal of the footbed
beneath these anterior ground contact points prevents medial
rolling through the forefoot. Removal of the footbed beneath the
1.sup.st and 5.sup.th metatarsal head contact points V5 and V6 will
substantially remove pronation through the forefoot.
[0056] Combinations with the other metatarsal heads can improve the
effect.
[0057] The degree to which pronation is resisted can be judged by
the correct lifting of the arches of the foot, the correct
simultaneous striking of the 1.sup.st and 5.sup.th metatarsal heads
on the footbed with no shifting of support towards the 1.sup.st
metatarsal support. There should be no medial rolling through the
heel, the midfoot or the forefoot. The knee should not collapse
inwards and provided all joints are reasonably free, the pelvis and
shoulders should be level.
[0058] The voids beneath the abutment ground contacts as described
should be large enough for the tissues of the sole of the foot to
sink into them and should provide a sufficient medial contact
surface along the void's medial edge to resist medial roll and
divert foot motion in an anterior direction. To this end,
rectangular or square voids are much better than circular voids,
which do not provide as great a surface area in contact with the
tissues of the sole of the foot to resist medial roll and direct
foot motion in an anterior direction. Circular voids can work if
the sides of the void are vertical and made with a material that
resists movement of the foot. Complete removal of the footbed
beneath an entire region of the foot e.g. the entire midfoot of a
strip across the entire foot, has a much reduced effect compared
with separate individual voids. Thus, a rectangular void is ideal
with the long edge of the rectangle placed in an anterior-posterior
direction. Chamferred internal edges are not advised as these
provide a surface for the foot to roll along. Hook and loop
material is not advisable as its surface is too firm and destroys
the effect. Individual small voids multiply the resistive
effect.
[0059] In the following description of embodiments of the
invention, the term footbed refers to a body of material with an
upper surface on which a foot rests in use. The body may constitute
the base of a shoe or other item of footwear, and thus be formed as
an integral part of the footwear, or it may take the form of a
separate insole which can be inserted into a pre-existing item of
footwear or directly attachable to the sole of the foot, for
example by suction or releasable adhesive. The term insole
encompasses a unitary item insertable into existing footwear to
form at least part of the footbed, or a plurality of separate
elements insertable into or attachable to an item of footwear to
form at least part of the footbed. The separate elements may be
releasably connectable to each other. The various areas of the
footbed will be described using the same terms and reference
numbers as the parts of the foot which overlie them in use. Thus,
the heel region 12 of the footbed refers to the part which will be
beneath the heel region 12 of the foot illustrated in FIG. 1, and
so on.
[0060] FIG. 2 shows a plan view of a footbed 20 in accordance with
a first embodiment of the present invention. The footbed 20 is
generally flat, but has a portion removed to leave a void in the
area V1. The void at V1 is within the lateral heel region beneath
the lateral part of the anterio-medial calcaneal ground contact
which extends into the lateral half of the heel. The void at V1
should have a minimum size of about 0.6 cm.sup.2 but can be all or
part of the region V1 illustrated in FIG. 2. In the direction
across the footbed, the void at V1 extends from the midline of the
foot, laterally to a point which is substantially aligned with the
lateral aspect of the 4.sup.th phalange. Thus, the void at V1 is
substantially aligned with the 4.sup.th phalange (4.sup.th toe). In
use the void at V1 removes contact with that part of the
anterio-medial calcaneal contact which allows pronation. It is
important that the void V1 does not extend across the midline into
the medial side, and that there is no balancing void to V1 on the
medial side of the calcaneus (other than at area V3) as such a void
negates the effect of a void at V1. A void V3 will resist a
balancing void placed in the medial heel which would otherwise
negate the effect achieved by a void in area V1.
[0061] Without pronation the arch of the foot is able to properly
firm up and the weight of the body is able to correctly move into
the mid foot as the gait cycle progresses. A roughly equal contact
with the footbed under the heads of the 1.sup.st and 5.sup.th
metatarsal joints gives equal support to forward transferred
weight; this does not occur with pronation.
[0062] The presence of void at V1 controls pronation until weight
reaches the middle of the mid foot and the heel starts to lift. At
this point weight is transferred through the anterio aspect of the
medial and lateral longitudinal arches and pronation can occur
through the anterior abutments under the heads of the metatarsals.
Voids in the footbed under areas V5 and any, or a combination, or
all of areas V6, V7, V8, V9 will stop this occurring.
[0063] This is illustrated by the dotted lines in FIG. 2 which
shows optional voids at V5 beneath the sesamoid bones beneath the
head of the 1.sup.st metatarsal, and beneath any, or a combination,
or all of V6 (beneath the tuberosity under the head of the 5.sup.th
metatarsal), V7, V8 and V9 (beneath the heads of the metatarsals 2,
3, and 4).
[0064] Voids under areas V7, V8 and V9 can be extended forwards to
lower or remove the footbed beneath the 2.sup.nd to the 5th toes.
This is helpful to remove pressure for people with hammer toes,
while preserving a void under the 2.sup.nd to 4th metatarsals.
[0065] The void at V1 (and voids in any of the other areas as
described above and further below) may be formed by complete
removal of material so that there is a hole all the way through the
footbed 20 from top to bottom. Alternatively, the void V1 may be
formed as a depression in the upper surface 24 of the footbed 20,
so that the upper surface 24 dips down in a certain area below the
level of the remaining area. The tissues of the sole of the foot
preferably should not be able to contact the floor of the void
which can then provide a surface for the foot to roll upon
depending on the sides of the void. The void can operate to tip the
foot in a certain direction, to resist movement by contact of the
tissues of the foot with an edge of the void, or by simply removing
a surface upon which the tissues of the foot can roll.
[0066] In another alternative, the upper surface 24 comprises a
thin, flexible layer which is continuous and extends over the void
at V1 (or any other void) so that the void is not visible, and in
order to prevent dirt accumulating in the void. However, such a
cover layer must be sufficiently thin and pliable so that it does
not itself support the foot and the soft tissues of the foot are
still able to deform into the void.
[0067] FIG. 3 illustrates a plan view of a footbed 20 in accordance
with another embodiment of the present invention. In this example,
the footbed 20 is again generally flat and a void is provided at
area V3 under the medial process of the tuber calcanei. In
addition, there may be voids at any, or a combination, or all of
the ground contacts at the following points: V1 (see before), V2
(lateral process of the tuber calcanei), V4 (anterio-lateral
calcaneal contact), V5, V6, V7, V8 and V9 (as described before).
These optional voids at V1, V2, and V4-V9 are shown in dotted
lines.
[0068] Optionally a void may also be provided in a central distal
portion V10 of the hallux 18a, which is shown in dotted lines, as
the distal phalanx of the Hallux provides a proximal force helping
to stabilise the anterior abutment of the medial longitudinal
arch.
[0069] In a further embodiment where the footbed 20 is generally
flat, in addition to voids in either or both of the lateral heel
and in area V3, one or more further voids may be provided in the
medial longitudinal arch area 14b or the lateral longitudinal arch
area 14c. If the footbed 20 has a raised mound in the medial arch
area, then one or more voids may be provided anywhere in the arch
areas 14a-14d.
[0070] The various embodiments described above relate to a footbed
where the supporting parts at the heel and the forefoot areas are
substantially on a level with each other, or there is a downward
slope from heel to forefoot of about 20.degree. or less to the
horizontal. Thus, this equates to substantially flat or low-heeled
footwear. In such footwear the mid tarsal joints are free and
pronation can occur through the mid foot, unless prevented by the
features of the present invention.
[0071] However, in footwear with higher heels, where the footbed
slopes from the heel to the forefoot at an angle of above about
20.degree., or the footwear is shaped so as to support the foot at
such an angle, the arch of the foot is fully firmed up and the mid
tarsals are locked. Movement at the TCN joint complex allows
rolling through the forefoot and hind foot. Such rolling occurs
about three pivot points, that is where the forefoot contacts the
footbed, at the contact of the heel with the footbed which in turn
acts on the ground via the heel of the shoe, and upwardly at the
person's hip. Movement about these three points can result in
inversion, where the sole of the foot tends to move towards the
median plane, and eversion, where the sole of the foot tends to
move away from the median plane.
[0072] Since the arch of the foot is raised, the lateral
longitudinal arch is unable to prevent excessive inversion through
the mid foot making it much easier to "turn" the ankle. This is
particularly true with stiletto heeled footwear where the pivoting
of the heel of the shoe is on a very fine point. From full
inversion to full eversion, the knee may be moving through nearly
180.degree., much more than when the footbed is substantially
flat.
[0073] Thus with high heels the anterio-medial and lateral arch
abutments must be stabilised. Any "rolling" of the foot at footbed
contact will cause a shift of body weight on the shoe. With a
stiletto heel this will make it much more likely that a complete
tipping over of the shoe will occur giving rise to a "turning" of
the ankle medially or laterally.
[0074] Stabilisation of the anterior abutments requires voids at V5
(under the 1.sup.st metatarsal head under the sesamoid bones) and
at V6 (under the tuberosity under the head of the 5.sup.th
metatarsal). Voids (V7, V8, V9) under heads of the metatarsals 2-4
also reduce rolling. Voids under the metatarsals should preferably
be separate voids and not one joined up void unless the sides of
the void are vertical.
[0075] The anterio-medial ground contact (V1 plus ground contact
crossing into the medial calcaneus) and areas V2 and V3 are the key
calcaneal contact points which allow rolling at the heel as they
are the posterior abutments, actual and functional. Voids beneath
all three points provide maximal resistance to heel rolling. A void
under the medial aspect of the anterio-medial calcaneal bony ground
contact prevents medial rolling as it is on the medial half of the
foot. A void under the lateral aspect of the same contact prevents
lateral rolling being on the lateral half of the foot. A void under
both aspects will reduce rolling both ways. Preferably the void
should be not much bigger than the area of the ground contact as
larger voids will permit a degree of rolling.
[0076] A void beneath the anterio-medial bony calcaneal ground
contact substantially reduces medial and lateral rolling whilst a
void only at V3 will reduce rolling medially, one only at V2 will
reduce rolling laterally.
[0077] Stabilising both anterior and posterior abutments has the
maximum effect in reducing rolling. Stabilising either the front or
the rear abutments separately will have some effect on reducing
rolling at the other.
[0078] In the various embodiments described above, the footbed 20
may comprise a single body of material, or it may consist of a
number of separate bodies of material. These separate bodies may be
releasably connectable to one another. The bodies may be
connectable directly to each other as shown in FIG. 5, or spaced
from each other but connected by means of straps or struts. The
releasable connection may be by means of hook and loop fasteners or
any other convenient fastening means. The releasable
interconnection allows a footbed to be tailored to a particular
user by combining and interchanging footbed parts of different
configurations.
[0079] The footbed 20 may take the form of a separate insole which
can be inserted into pre-existing footwear.
[0080] Alternatively, the footbed may be formed integrally into an
item of footwear such as a shoe, boot or sandal. The footbed 20 may
also be formed integrally with a flexible sock 28 or stocking as
shown in FIG. 6.
[0081] The user could then simply wear existing footwear over the
sock 28. Alternatively, the sock itself could constitute an item of
footwear in its own right. This could be worn indoors in the manner
of known "slipper socks" (which are simply socks with anti-slip
material on the lower surface) or, if made from suitably durable,
waterproof material it could be worn for outdoor use.
[0082] FIGS. 7a-c show alternatives (schematically and not to
scale) of a footbed 20 in which at least part of the forefoot area
is raised relative to the anterio-medial calcaneal ground contact
of the heel area. In particular, the forefoot area 16 which in use
will receive at least the parts of the foot beneath the 1.sup.st
and 5.sup.th metatarsal heads is raised relative to the heel
anterior-medial calcaneal ground contact of the area 12 by at least
0.5 cm. In its simplest form, the footbed may consist of two pads
which in use receive the 1.sup.st and 5.sup.th metatarsal joints
and thus raise these parts of the foot by at least 0.5 cm relative
to the anterio-medial calcaneal ground contact of the heel. In this
case, the toes would also be lower than the 1.sup.st and 5.sup.th
metatarsals.
[0083] However, the footbed may extend beyond the metatarsal area
to include an area for receiving the toes and optionally also an
area for receiving the heel.
[0084] For example, as in FIG. 7a the toe and heel areas may be
substantially flat and level with each other, while the metatarsal
area at least beneath the 1.sup.st and 5.sup.th metatarsals is
raised.
[0085] Alternatively, as in FIG. 7b, the toe and metatarsal areas
are substantially flat and level with each other, while the heel
area is lowered.
[0086] In another alternative, the heel itself can be free to `tip`
forward and down. One method is to have a taper under the heel from
back to front with a joint 26 between the heel and the rest of the
footbed, allowing the heel part to tilt as indicated by the arrows
in FIG. 7c. In this way, as the weight of the body reaches the
medial anterior cancaneal ground contact, the front of the heel
drops down below the rest of the footbed slightly. This both
creates a void at V1 and lowers the heel relative to the 1.sup.st
and 5.sup.th metatarsal head ground contacts.
[0087] Further the outer sole of the shoe in contact with the
ground at least in the mid foot (if present) and in the forefoot
should preferably be generally flat with no form of "rocker"
present. Such an arrangement has advantages over a footbed which
slopes upward such that the distal phalanx of the hallux contacts
the footbed at the same time as the 1.sup.st and 5.sup.th
metatarsal heads as increased pressure is placed on the anterior
aspect of the ankle. This is removed by the footbed under the
distal phalanges being flat or level with or lower than the
1.sup.st and 5.sup.th metatarsal heads. If higher, the slope up
should be no more than 5 degrees.
[0088] The absence of a rocker beneath the midfoot or forefoot is
important as this increases stability in walking and a rocker
action in the forefoot increases pressure on the ankle and knee
during "toe off".
[0089] A footbed with support only under the 1.sup.st and 5.sup.th
metatarsal heads, or under the forefoot, or under the forefoot and
midfoot, also works leaving the heel to rest on the ground.
Alternatively the footbed may support the whole foot but with the
1.sup.st and 5.sup.th metatarsal heads raised relative to the heel
by at least 0.5 cm. A footbed with support under the heel and under
the forefoot without a midfoot also works. All of these options
prevents pronation provided the relative difference in height
between the anterio-medial ground contact and the 1.sup.st and
5.sup.th metatarsal heads is at least 0.5 cm, the calcaneal ground
contact being lower than the metatarsal. In this way the arches of
the foot can "firm up" before rolling takes place.
[0090] Thus, the present invention provides an improved footbed
which alters the support provided to a foot in order to halt
pronation. It will be appreciated that the precise configuration of
the footbed may take many forms and the details can be varied from
those shown in the attached drawings without departing from the
scope of the claims. Further optional features may also be
provided.
[0091] For example, the footbed 20, whether separate or integrally
formed with an item of footwear, may initially be provided with a
continuous upper surface 24 with sections which are optionally
removable to create one or more of the voids as discussed above so
that the user, having purchased the footbed 20, can remove portions
as required to give a choice of possible configurations.
[0092] It will also be appreciated that while a single void is
illustrated in each of the various areas of V1-V10, each area may
in fact include more than one void. The embodiments above also
cover the situation where the footbed 20 is built up around the
ground contact points described so as to leave a void at the
claimed points, sufficient to prevent pronation.
[0093] The footbed can be formed by a very thin layer of
particulate material, at least at the bony ground contact points in
the heel and under the metatarsals as previously described. When a
person stands on such a footbed, the particulate naturally moves
under the person's weight in order to create voids in the necessary
areas. The layer should be thin enough that it does not compact
into a solid firm layer for the effect to work.
* * * * *