Note: Descriptions are shown in the official language in which they were submitted.
CA 02322405 2000-10-OS
WORK INSOLES
BACKGROUND OF THE INVENTION
The present invention relates generally to insoles
for footwear, and more particularly, to improved
insoles particularly adapted for working people that
spend much time on their feet.
There are many working people, such as
construction workers, cashiers, etc., that spend most
of their working time in a standing position. Further,
much of this standing occurs on hard floors, such as
concrete floors or the like. This has the tendency to
cause lower back pain and lower extremity pain.
As a result of this pain, working people tend to
alter their posture and gait, in an attempt to
alleviate this pain.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present
invention to provide an insole that overcomes the
problems with the aforementioned prior art.
It is another object of the present invention to
provide an insole that relieves lower back pain and
lower extremity pain.
It is still another object of the present
invention to provide an insole which works faster and
better than conventional insoles in relieving lower
back pain and lower extremity pain.
It is yet another object of the present invention
to provide an insole that provides cushioning and shock
absorption at every point along the foot stride.
It is a further object of the present invention to
provide an insole that provides additional shock
absorption where needed at high force areas along the
foot stride.
It is a still further object of the present
invention to provide an insole that provides a
biomechanical effect in rolling through the gait, to
enhance the stance and correct gait of the foot.
CA 02322405 2000-10-OS
2
In accordance with an aspect of the present
invention, a full length insole for use with footwear,
comprises a first layer including a forefoot portion
extending at least to metatarsals of a foot, a heel
portion, a mid portion connecting together the forefoot
portion and the heel portion, an upper surface
extending along the forefoot, mid and heel portions and
on which a person stands, and a lower surface extending
along the forefoot, mid and heel portions, the lower
surface including a shallow recess, the first layer
being made of a material of a first hardness; and a
force line insert secured in the recess and having a
shape that follows a greatest area of force of the foot
on the upper surface during a normal stride, the force
line insert being made of a material of a second
hardness which is less than the first hardness.
The recess and the force line insert preferably
each have a height of approximately 2 mm. Also, the
force line insert and the recess have substantially the
same shape and dimensions. Preferably, the first layer
is made from a urethane foam having a Shore "00"
durometer hardness in the range of approximately 45-75,
with a more preferred range of approximately 55-65, and
with a preferred value of approximately 60, and the
force line insert is made from a urethane foam having a
Shore "00" durometer hardness in the range of
approximately 35-65, with a preferred range of
approximately 45-55, and with a preferred value of
approximately 50.
The force line insert includes a heel insert
portion having a first width for accommodating a heel
of the foot during a heel strike and to provide
cushioning thereof; a mid insert portion connected at
one end with the heel insert portion and which has a
second width less than the first width; and a forefoot
insert portion connected with an opposite end of the
mid insert portion and which has a shape that extends
forwardly to a greater extent at a medial side of the
CA 02322405 2000-10-OS
3
insole in correspondence with a positioning of the
metatarsals of the foot. Preferably, a forward edge of
the forefoot insert portion has an angled arcuate
shape.
In addition, the heel portion of the insole is
cupped to maintain the heel in the heel portion.
The mid portion includes a medial arch portion
positioned adjacent to the mid insole portion. The
medial.arch portion has a height greater than a
remainder of the mid portion, and includes spaced
apart, transverse oriented grooves defining transverse
flex members therebetween which effectively function as
springs.
In accordance with another aspect of the present
invention, a full length insole for use with footwear,
comprises a forefoot portion extending at least to
metatarsals of a foot; a heel portion; a mid portion
connecting together the forefoot portion and the heel
portion, the mid portion including a medial arch
portion; an upper surface extending along the forefoot,
mid and heel portions on which a person stands; a lower
surface extending along the forefoot, mid and heel
portions; a forefoot pillow formed as a raised area at
the upper surface at the forefoot portion to provide
additional cushioning thereat and shaped to conform to
a pressure area of the foot so as to include a front
edge that extends forwardly to a greater extent at a
medial side of the insole; and a heel pillow formed as
a raised area at the upper surface at the heel portion
to provide additional cushioning thereat and shaped to
enhance progression of a gait to guide the foot toward
the medial arch portion.
The forefoot and heel pillows provide an extra
thickness of the same material as a remainder of the
insole at the forefoot and heel portions, and are
formed integrally as a single molded piece therewith.
The extra thickness is less than approximately 3 mm.
CA 02322405 2000-10-OS
4
The heel pillow has a shape of a wing that is
oriented rearwardly. The wing has a greater width at a
rear portion thereof and tapers in width in a forward
direction, while also pointing toward the medial arch
portion.
In accordance with still another aspect of the
present invention, a full length insole for use with
footwear, comprises a first layer including a forefoot
portion extending at least to metatarsals of a foot, a
heel portion, a mid portion connecting together the
forefoot portion and the heel portion, the mid portion
including a medial arch portion, an upper surface
extending along the forefoot, mid and heel portions on
which a person stands, and a lower surface extending
along the forefoot, mid and heel portions, the lower
surface including a shallow recess, the first layer
being made of a material of a first hardness; a force
line insert secured in the recess and having a shape
that follows a greatest area of force of the foot on
the upper surface during a normal stride, the force
line insert being made of a material of a second
hardness which is less than the first hardness; a
forefoot pillow formed as a raised area at the upper
surface at the forefoot portion to provide additional
cushioning thereat and shaped to conform to a pressure
area of the foot so as to include a front edge that
extends forwardly to a greater extent at a medial side
of the insole; and a heel pillow formed as a raised
area at the upper surface at the heel portion to
provide additional cushioning thereat and shaped to
enhance progression of a gait to guide the foot toward
the medial arch portion.
The above and other features of the invention will
become readily apparent from the following detailed
description thereof which is to be read in connection
with the accompanying drawings.
CA 02322405 2000-10-OS
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a top plan view of a left insole
according to the present invention;
Fig. 2 is a top plan view of a right insole
5 according to the present invention;
Fig. 3 is a bottom plan view of the right insole
of Fig. 2;
Fig. 4 is a bottom plan view of the left insole of
Fig. 1;
Fig. 5 is a cross-sectional view of the left
insole, taken along line 5-5 of Fig. 1;
Fig. 6 is a cross-sectional view of the left
insole, taken along line 6-6 of Fig. 1; and
Fig. 7 is a cross-sectional view of the left
insole, taken along line 7-7 of Fig. 1.
DETAILED DESCRIPTION
As discussed above, there are many working people,
such as construction workers, cashiers, etc., that
spend most of their working time in a standing
position. Further, much of this standing occurs on
hard floors, such as concrete floors or the like. This
has the tendency to cause lower back pain and lower
extremity pain. Further, these people also tend to
alter their posture and gait, in an attempt to
alleviate this pain.
The present invention is designed to alleviate
such lower back pain and lower extremity pain, while
enhancing the stance and correct gait of the foot.
Referring to the drawings in detail, a left insole
10 and a right insole 11 according to the present
invention are adapted to be placed in articles of
footwear, as is well known. Insoles 10 and 11 are
particularly adapted to alleviate lower back pain and
lower extremity pain. Only the left insole 10 will now
be described, with the understanding that right insole
11 will be the mirror image of insole 10.
CA 02322405 2000-10-OS
6
Specifically, insole 10 has the shape of a human
left foot and therefore includes a curved toe or
forefoot portion 12, a heel portion 14, and a mid
portion 16 which connects forefoot portion 12 and heel
5 portion 14 together. Heel portion 14 has a greater
thickness than toe portion 12. For example, heel
portion 14 can have a thickness of about 5-8 mm, while
toe portion can have a thickness of about 1-6 mm.
Insole 10 is formed by a lower layer 18 and a top
cover 20 secured to the upper surface of lower layer
18, along forefoot portion 12, cupped heel portion 14
and mid portion 16, by any suitable means, such as
adhesive, RF welding, etc.
Lower layer 18 can be made from any suitable
15 material including, but not limited to, any flexible
material which can cushion and absorb the shock from
heel strike on the insole. Suitable shock absorbing
materials can include any suitable foam, such as but
not limited to, cross-linked polyethylene,
20 polyethylene-vinyl acetate), polyvinyl chloride,
synthetic and natural latex rubbers, neoprene, block
polymer elastomer of the
acrylonitrile-butadiene-styrene or
styrene-butadienestyrene type, thermoplastic
25 elastomers, ethylenepropylene rubbers, silicone
elastomers, polystyrene, polyurea or polyurethane; most
preferably a polyurethane foam made from flexible
polyol chain and an isocyanate such as a monomeric or
prepolymerized diisocyanate based on
30 4,4'-diphenylmethane diisocyanate (MDI) or toluene
diisocyanate (TDI). Such foams can be blown with
freon, water, methylene chloride or other gas producing
agents, as well as by mechanically frothing to prepare
the shock absorbing resilient layer. Such foams
35 advantageously can be molded into the desired shape or
geometry. Non-foam elastomers such as the class of
materials known as viscoelastic polymers, or silicone
gels, which show high levels of damping when tested by
CA 02322405 2000-10-OS
7
dynamic mechanical analysis performed in the range of
-50 degrees C to 100 degrees C may also be
advantageously employed. A resilient polyurethane can
be prepared from diisocyanate prepolymer, polyol,
catalyst and stabilizers which provide a waterblown
polyurethane foam of the desired physical attributes.
Suitable diisocyanate prepolymer and polyol components
include polymeric MDI M-10 (CAS 9016-87-9) and
Polymeric MDI MM-103 (CAS 25686-28-6), both available
from BASF, Parsippany, N.J.; Pluracol 945 (CAS
9082-00-2) and Pluracol 1003, both available from BASF,
Parsippany, N.J.; Multrinol 9200, available from Mobay,
Pittsburgh, Pa.; MDI diisocyanate prepolymer XAS
10971.02 and polyol blend XUS 18021.00 available from
the Dow Chemical Company, Midland, Mich.; and Niax
34-28, available from Union Carbide, Danbury, Conn.
These urethane systems generally contain a surfactant,
a blowing agent, and an ultra-violet stabilizer and/or
catalyst package. Suitable catalysts include Dabco
33-LV (CAS 280-57-9,2526-71-8), Dabco X543 (CAS Trade
Secret), Dabco T-12 (CAS 77-58-7), and Dabco TAC (CAS
107-21-1) all obtainable from Air Products Inc.,
Allentown, Pa.; Fomrez UL-38, a stannous octoate, from
the Witco Chemical Co., New York, N.Y. or A-1(CAS
3033-62-3) available from OSI Corp., Norcross, Ga.
Suitable stabilizers include Tinuvin 765 (CAS
41556-26-7), Tinuvin 328 (CAS 25973-55-1), Tinuvin 213
(CAS 104810-48-2), Irganox 1010 (CAS 6683-19-8),
Irganox 245 (CAS 36443-68-2), all available from the
Ciba Geigy Corporation, Greensboro, N.C., or Givsorb
UV-1 (CAS 057834-33-0) and Givsorb UV-2 (CAS
065816-20-8) from Givaudan Corporation, Clifton, N.J.
Suitable surfactants include DC-5169 (a mixture), DC190
(CAS68037-64-9), DC197 (CAS69430-39-3), DC-5125 (CAS
68037-62-7) all available from Air Products Corp.,
Allentown Pa. and L-5302 (CAS trade secret) from Union
Carbide, Danbury Conn. Alternatively, lower layer 18
can be a laminate construction, that is, a multilayered
CA 02322405 2000-10-OS
8
composite of any of the above materials. Multilayered
composites are made from one or more of the above
materials such as a combination of polyethylene vinyl
acetate and polyethylene (two layers), a combination of
polyurethane and polyvinyl chloride (two layers) or a
combination of ethylene propylene rubber, polyurethane
foam and ethylene vinyl acetate (3 layers).
Preferably, lower layer 18 is made from a urethane
molded material.
l0 Top cover 20 can be made from any suitable
material including, but not limited to, fabrics,
leather, leatherboard, expanded vinyl foam, flocked
vinyl film, coagulated polyurethane, latex foam on
scrim, supported polyurethane foam, laminated
polyurethane film or in-mold coatings such as
polyurethanes, styrene-butadiene-rubber,
acrylonitrile-butadiene, acrylonitrile terpolymers and
copolymers, vinyls, or other acrylics, as integral top
covers. Desirable characteristics of top cover 20
include good durability, stability and visual
appearance. It is also desirable that top cover 20
have good flexibility, as indicated by a low modulus,
in order to be easily moldable. The bonding surface of
top cover 20 should provide an appropriate texture in
order to achieve a suitable mechanical bond to the
upper surface of lower layer 18. Preferably, the
material of top cover 20 is a fabric, such as a brushed
knit laminate top cloth (brushed knit fabric/urethane
film/non-woven scrim cloth laminate) or a urethane knit
laminate top cloth. Preferably, top cover 20 is made
from a polyester fabric material.
Lower layer 18 can be prepared by conventional
methods such as heat sealing, ultrasonic sealing,
radio-frequency sealing, lamination, thermoforming,
reaction injection molding, and compression molding
and, if necessary, followed by secondary die-cutting or
in-mold die cutting. Representative methods are
taught, for example, in U.S. Pat. Nos. 3,489,594;
CA 02322405 2003-03-14
3,530,489 4,257,176; 4,185,402; 4,586,273, in the
Handbook of Plz~stics, Herber R. Simonds and Carleton
Ellis, 1943, New York, N.Y., Reaction Injection Molding
Machinery and Processes, F. Melvin Sweeney, 1987, New
York, N.Y., and F:Lexible Polyurethane Foams, George
Woods, 1982, New Jersey, preferably, the
innersole is prepared by a foam reaction molding
process such as taught in U.S. Pat. No. 4,694,589.
During use, insole 10 is placed in a shoe so that
the medial side of mid portion 16 rests against the
inside of the shoe. Forefoot portion 12 may end just
in front of the metatarsals. However, insole 10 is
preferably a full length insole, that is, extends along
the entire foot.
Typically, insole 10 would be sized corresponding
to shoe sizes and would be provided in sized pairs.
Alternatively, insole 10 may be trimmed to the
requirements of the user. In this regard, arcuate
pattern trim lines 22a-22d may be formed an the lower
surface of forefoot portion 12 of insole lo, and which
are representative of various sizes of the human foot.
For example, insole 10 may be provided for a woman's
shoe size of 10-11, with first continuous pattern trim
line 22a being representative of a smaller size insole
for a woman's shoe size 9, second continuous pattern
trim line 22b extending around the periphery of toe
portion 12 indicative of another size of insole for a
woman's shoe size 8, third continuous pattern trim line
22c extending around the periphery of toe portion 12
indicative of another size of insole for a woman's shoe
size 7, and fourth continuous pattern trim line 22d
extending around the periphery of toe portion 12
indicative of another size of insole for a woman's shoe
size 6. If the user requires a size other than the
original large size, the wearer merely trims the insole
with a scissors or cutting instrument, using pattern
trim lines 22a-22d, to achieve the proper size. The
CA 02322405 2000-10-OS
pattern trim lines may be imprinted by conventional
printing techniques, silkscreening and the like. As an
alternative, pattern trim lines 22a-22d may be formed
as shallow grooves, or be perforated, so that a smaller
5 size insole may be separated by tearing along the
appropriate trim lines, which tearing operation is
facilitated by the inclusion of perforations. Thus,
forefoot portion 12 can be trimmed so that forefoot
portion 12 fits within the toe portion of a shoe.
10 In accordance with the present invention, insole
10 is formed with a structure to alleviate lower back
pain and lower extremity pain. Specifically, insole 10
is provided with a shallow recess 24 about 2 mm deep at
the lower surface of lower section 18. Shallow recess
24 follows the greatest line of force of the foot
during a normal stride, that is, in a single limb
stance phase. When walking, the foot first impacts at
the heel with a large force, for example, up to three
times a normal standing force, and then moves toward
the forefoot. The heel lifts off of the insole
slightly at the position of contact of the mid-foot
with the insole and then transfers to the forefoot. At
the forefoot, the foot transfers from the position of
the fifth metatarsal to the first metatarsal, where
push-off occurs at the big toe of the foot.
Shallow recess 24 has a shape to follow this line
of force, and to cover the high force areas during this
stride.
In accordance with the present invention, a force
line insert 26 having a thickness of about 2 mm and
having the same shape as shallow recess 24, is secured
within shallow recess. Force line insert 26 is made
from a softer or more cushioning material than the
remainder of lower section 18 of insole 10. For
example, lower section 18 of insole 10 can be made from
a urethane foam having a Shore "00" durometer hardness
in the range of approximately 45-75., more preferably in
the range of approximately 55-65, and with a preferred
CA 02322405 2000-10-OS
11
hardness of approximately 60, while force line insert
26 can be made from a softer urethane foam having a
Shore "00" durometer hardness in the range of
approximately 35-65, more preferably in the range of
approximately 45-55, and with a preferred hardness of
approximately 50. A preferred material for force line
insert 26 is the material sold by Rogers Corporation of
Rogers, Connecticut under the trademark "PORON".
Preferably, force line insert 26 is formed first, and
then placed in a mold, where the remainder of lower
section 18 of insole 10 is molded thereon, and thereby
bonded to the PORON material of force line insert 26
during the molding operation.
Thus, the force line shape of insert 26 provides a
softer material along the center of pressure of the
gait line. As a result, force line insert 26 provides
cushioning and shock absorption at every point along
the stride.
As shown, force line insert 26 includes a heel
insert portion 26a of a width intended to accommodate
the heel during the heel strike and provide cushioning
thereof. From heel insert portion 26a, insert 26
tapers in width to a mid insert portion 26b at mid
portion 16. The reason for the taper is that the
cushioning material of insert 26 is not needed as much
at this position, since there is more surface area of
the foot in contact with the upper surface of insole 10
to spread out the forces more evenly, and because, as
will be explained hereinafter, the foot is guided
toward medial arch portion 16a of mid portion 16 which
absorbs much of the forces.
From mid insert portion 26b, insert 26 increases
in width to a forefoot insert portion 26c. Forefoot
insert portion 26c has a shape that extends forwardly
to a greater extent at the medial side of insole 10 in
correspondence with the configuration of the
metatarsals. As a result, the forward edge of forefoot
insert portion 26c has an angled arcuate shape.
CA 02322405 2000-10-OS
12
Thus, with the initial heel strike, heel insert
portion 26a functions to provide greater cushioning and
shock absorbing at the heel. As the foot moves
forwardly, there is still a line of contact at the mid-
foot, but medial arch portion 16a also absorbs much of
the force, so as to provide an evening out of the force
at the mid-foot. As a result, the width of mid insert
portion 26b can be reduced. Thereafter, the foot
transfers to the forefoot, and particularly, from the
fifth metatarsal to the first metatarsal, where push-
off occurs at the big toe of the foot. Such force can
be up to three times the normal standing force.
Forefoot insert portion 26c is shaped to follow this
line of force, and provide extra cushioning and shock
absorbing during this action.
It will be appreciated that heel portion 14 is
preferably a cupped heel portion. Specifically, as
shown, heel portion 14 includes a relatively flat
central portion 14a, and a sloped side wall 14b that
extends around the sides and rear of central portion
14a. Generally, when a heel strikes a surface, the fat
pad portion of the heel spreads out. The cupped heel
portion thereby stabilizes the heel of the person and
maintains the heel in heel portion 14, to prevent such
spreading out of the fat pad portion of the heel, and
to also prevent any side to side movement of the heel
in heel portion 14. This ensures that heel insole
portion 26a operates properly on the foot.
With respect to medial arch portion 16a, the arch
can be built into insole 10 in one of two ways. First,
arch portion 16a can be filled or built up with a bulky
cushioning material. This, however, provides the
disadvantage that it might not be capable of use in a
shoe already having a built in arch support, since it
may be too bulky. Therefore, the preferred manner of
forming medial arch portion 16a according to the
present invention is to build up the height of medial
arch portion 16a, but to provide spaced apart,
CA 02322405 2000-10-OS
13
transverse oriented grooves or recesses 28 therein,
which define transverse flex members 30 therebetween
which effectively function as springs. The advantage
of using flex members 30 is that the bulk of arch
portion 16a is not needed and thereby greatly reduced.
It therefore becomes easier and better to use flex
members 30 with shoes, since they can be used in shoes
with or without a built in arch support.
Flex members 30 function in concert with force
line insert 26 to provide even cushioning support and
shock absorption over the entire mid-foot area during
mid-stance phase. Because of flex members 30, the
width of mid insole portion 26b can be reduced. The
use of flex members 30, by themselves, however, has
been known in insoles sold more than one year ago, but
the combination with force line insert 26 is new.
In addition to force line insert 26, another
important feature of the present invention is the
addition of forefoot pillow 32 and heel pillow 34.
Pillows 32 and 34 provide an extra thickness of
the same material as lower layer 18 and are formed
integrally as a single piece therewith during the
molding operation of insole 10. Pillows 32 and 34 are
provided at the two areas with the greatest force.
Since the cushioning energy is directly proportional to
thickness, the cushioning effect is normally achieved
with increasing bulk of the entire insole. The present
invention accomplishes this by increasing the bulk
slightly by up to approximately 3 mm in thickness above
the upper surface of the insole, only at the areas
where the greatest forces result during walking.
When walking, the heel of the foot normally hits
on the outside of the heel and rolls toward the medial
arch. Thus, pillow 34, in addition, to providing
cushioning at the heel, is shaped to enhance the
rolling or progression of the gait, and thereby guides
the foot toward medial arch portion 16a. Thus, heel
pillow 34 functions as a guide as well as providing
CA 02322405 2000-10-OS
14
extra cushioning. In this regard, pillow 34 has the
shape of a wing that is oriented rearwardly. Thus,
pillow 34 has a greater width at the rear portion and
tapers in width, while also pointing toward medial arch
portion 16a.
At the forefoot, pillow 32 provides the same two
functions. Normally, when walking, the foot moves from
the fifth metatarsal to the first metatarsal and then
the person pushes off from the big toe. Pillow 32
thereby has a shape similar to forefoot insole portion
26c, that is, with an arcuate front edge that extends
forwardly to a greater extent at the medial side of
insole 10.
Pillows 32 and 34 thereby enhance the stance and
correct walking gait, while also providing cushioning.
Thus, while force line insert 26 provides
cushioning and shock absorption at every point, pillows
32 and 34 provide a different function of shock
absorption where needed, as well as a biomechanical
effect in aiding the foot in rolling through the gait.
Tests were performed with insoles 10 and 11.
Specifically, 103 people were evaluated over a four
week period with insoles 10 and 11.
The following Table I shows a four week period of
people wearing insoles 10 and 11 on a visual analog
scale (VAS), which is a widely accepted method for
evaluating pain.
TABLE I
Variable Number of Mean VAS Standard
(Back Pain) Subjects Score Deviation
Baseline
(week 0) 104 57.57 14.89
Week 1 103 37.17 20.12
Week 2 103 30.81 19.93
Week 4 103 22.48 20.50
CA 02322405 2000-10-OS
It will be appreciated that the back pain
significantly decreased from the baseline to week 1,
and continued to decrease thereafter to week 4.
Similar tests with conventional insoles show that,
5 although many insoles normally relieve some pain, the
present invention works faster and better than
conventional insoles that provide shock absorption.
Thus, the results of the tests with insoles 10 and 11
showed significant relief of lower back pain and lower
l0 extremity pain.
The change in back pain VAS score from the
baseline is shown by the following Table II:
TABLE II
15 Variable
(Change in
Back pain Mean change Standard
VAS) in VAS score Deviation Prob>~T~
Week 1 from
Baseline 20.19 22.15 0.0001
Week 2 from
Baseline 26.81 22.93 0.0001
Week 4 from
Baseline 35.14 23.90 0.0001
In Table II, the designation Prob>~T~ refers to
the probability that the data is significantly accurate
and relevant. The small percentage confirms the
accuracy and relevancy of the data.
The same analysis was performed with the lower
extremity pain, and is presented in Tables III and IV
below:
CA 02322405 2000-10-OS
16
TABLE III
Variable
(Lower
Extremity Number of Mean VAS Standard
Pain) Subjects Score Deviation
Baseline
(week O) 104 35.56 23.00
Week 1 103 27.13 20.43
Week 2 103 25.32 22.10
Week 4 103 19.94 21.50
TABLE IV
Variable
(Change in
Lower
Extremity Mean change Standard
Pain VAS) in VAS score Deviation Prob>~T~
Week 1 from
Baseline 8.01 21.19 0.0002
Week 2 from
Baseline 10.07 23.03 0.0001
Week 4 from
Baseline 15.46 24.15 0.0001
Subjective tests were also performed. At baseline
week 0, 98% of the subjects considered insoles 10 and
11 moderately, very or extremely comfortable. At week
4, 92.3% considered the insoles moderately, very or
extremely effective in relieving pain. Also, at week
4, over 80% of the subjects considered that insoles 10
and 11 were moderately, very or extremely effective in
relieving tired, achy feet (83.5%) as well as tired,
achy legs (81.3%).
Thus, insoles 10 and 11 provided significant
relief of lower back pain and lower extremity pain
after only one week, with further decreases in pain in
weeks 2 and 4.
Although the present invention. uses the term
insole, it will be appreciated that the use of other
CA 02322405 2000-10-OS
17
equivalent or similar terms such as innersole or insert
are considered to be synonymous and interchangeable,
and thereby covered by the present claimed invention.
Further, although the present invention has been
described in connection with insoles, the present
invention can be incorporated directly into the sole of
a shoe, and the present invention is intended to cover
the same. In this regard, reference is made in the
claims~to a full length insole for use with footwear,
which can include a removable insole or an insole built
into a shoe.
Having described specific preferred embodiments of
the invention with reference to the accompanying
drawings, it will be appreciated that the present
invention is not limited to those precise embodiments
and that various changes and modifications can be
effected therein by one of ordinary skill in the art
without departing from the scope or spirit of the
invention as defined by the appended claims.
