Patent Application
20090031583
Knee pain is a common problem having various causes, including arthritis and sports injuries. When knee pain sufferers are standing, walking, or running, the pain is typically heightened, as increased forces are transmitted through the knees. While known footwear and known shoe inserts can limit shock on the knees, additional knee pain relief may be sought.
Some example embodiments of the present invention have been shown to be particularly effective in alleviating knee pain when compared to other foot supports, such as many commonly available shoe inserts. A particularly effective configuration has been found to be a pre-manufactured shoe insert including a depression beneath the “big toe,” i.e. beneath the first proximal phalange, in conjunction with a medial post of approximately 4.5°.
According to some example embodiments of the present invention, some example foot supports may be full-length pre-manufactured shoe inserts having a compressible foam body having a forefoot region configured to underly the metatarsal heads and proximal phalanges of a wearer's foot, where the forefoot region has a toe-lowering section that underlies at least one of a first proximal phalange and a first metatarsal head of the wearer's foot. In some examples, the body may have a heel region underlying the heel of the wearer's foot that has a medial post. In some examples, the body has a midfoot region between the forefoot region and the heel region and having a raised portion underlying the medial arch of the wearer's foot configured to support the medial arch of the wearer's foot. Some examples may have a support member underlying and coupled to the heel region and at least part of the midfoot region of the body. In some examples, the support member has greater stiffness than the body. In some examples, the support body has an aperture underlying the heel region of the body. In some examples, the body extends into the aperture.
Some example foot supports, according to some example embodiments of the present invention, may have a body having a forefoot region that underlies the metatarsal heads and proximal phalanges of a wearer's foot, a raised arch support that underlies and provides support to the medial arch of the wearer's foot, and a toe-lowering section in the forefoot region that underlies at least the first proximal phalange but less than all of the proximal phalanges of the wearer's foot. Some examples have a toe-lowering section that underlies at least the first proximal phalange but less than all of the proximal phalanges of the wearer's foot. Some examples may have a toe-lowering section that extends in a rearward direction to underlie at least the first metatarsal head. Some examples may have a depression that extends to a forward edge of a forefoot region. Some examples may have a heel region configured to underly the heel of the wearer's foot, the heel region having a medial post. In some examples, the medial post may be between 1° and 8°. In some examples, the medial post is between 3° and 6°. In some examples, the medial post is approximately 4.5°. In some examples, the toe-lowering section includes a depression. In some examples, the depression is disposed on a bottom surface of the body, the bottom surface facing away from the wearer's foot. In some examples, the toe-lowering section has an area of greater compressibility than areas of the forefoot region adjacent to the tow-lowering section. In some examples, the body is made of a foam having a shore OO hardness between 40 and 60. In some examples, the foam has a shore OO hardness of approximately 47. In some examples, the foam has a cushioning energy of between 50 and 200 N-mm. In some examples, the foam has a cushioning energy of approximately 80 N-mm.
Some example foot supports, according to some example embodiments of the present invention, may have a body having a substantially planar forefoot region configured to underly the metatarsal heads and proximal phalanges of a wearer's foot, the forefoot region having a first thickness. Some examples have a substantially planar depression region disposed in the forefoot region. In some examples, the depression region spans less than the width of the forefoot region and underlies at least one proximal phalange of the wearer's foot. In some examples, the depression region has a second thickness, the second thickness being less than the first thickness.
Some example foot supports, according to some example embodiments of the present invention, may have a body having a forefoot region that underlies the metatarsal heads and proximal phalanges of a wearer's foot. Some examples have a depression in the forefoot region underlying at least one of the first metatarsal head and the first proximal phalange. Some examples have a heel region that underlies the heel of the wearer's foot and has a medial post.
Some example foot supports, according to some example embodiments of the present invention, may have a forefoot region that supports at least one proximal phalange of a wearer's foot at a higher position than the first proximal phalange of a wearer's foot when weight is applied to the wearer's foot, and a heel region having a medial post.
Some example foot supports, according to some example embodiments of the present invention, may have a body having a forefoot region that underlies the metatarsal heads and proximal phalanges of a wearer's foot, a raised arch support that underlies and provides support to the medial arch of the wearer's foot, a toe-lowering section in the forefoot region that underlies at least the first proximal phalange but less than all of the proximal phalanges of the wearer's foot, and a heel section that inverts (i.e. supinates or inwardly rolls) the wearer's subtalar joint when the insert is worn. In some examples the heel section inverts the wearer's subtalar joint by between 1° and 8°. In some examples, the heel section inverts the wearer's subtalar joint by between 3° and 6°. Some examples have a heel section that inverts the wearer's subtalar joint by approximately 4.5°. Some examples have a body is made of a foam having a shore OO hardness between 40 and 60. In some examples, the foam has a shore OO hardness of approximately 47. According to some examples, the body is made of a foam having a cushioning energy of between 50 and 200 N-mm. In some examples, the foam has a cushioning energy of approximately 80 N-mm.
Foot supports include, e.g., shoe inserts, shoes with specially designed insoles, and sandals. The primary focus, however, is on mass-produced pre-manufactured shoe inserts.
In the forefoot re-ion 50 is a toe-lowering, section 80 that underlies the first proximal phalange of the wearer's foot. The toe-lowering operates to maintain a position of at least one of the first proximal phalange and the first metatarsal head below the position of other proximal phalanges and/or metatarsal heads. Although the toe-lowering section of
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In the forefoot region 50 are a plurality of cut lines 151 shaped and sized to roughly approximate the inner boundary of multiple shoe sizes. If, for example, the foot support 10 is a shoe insert, this may be used to allow the wearer to trim the foot support to fit his or her particular foot size. To further accommodate different foot sizes, the toe-lowering section 80 may be dimensioned such that it extends rearwardly far enough to underlie the first phalanges or the first phalanges and the first metatarsal heads of wearers of at least two different shoe sizes. In embodiments configured to accommodate multiple sizes of wearers with the same insole model, trimming lines may be provided. It will be appreciated that the example embodiment shown in the figure, a single size insert is configured for use in a broad range of shoe sizes. Thus, the toe-lowering section 80 is configured to underlie the first metatarsal heads of most wearers across a broad range of sizes, although depending on the exact size and anatomy of a particular wearers foot, the depression may only partially underlie the metatarsal head, and in some extreme cases the depression may not actually reach the metatarsal head. It will be appreciated that the number of such cases can be further reduced by having a greater range of sizes for the example insole, although this would come at a cost of having additional models.
Testing has indicated that some example shoe inserts made according to the present invention are effective in relieving knee pain due to overpronation. In this regard, four shoe inserts according to the present invention were tested, (1) Men's Insole Version A; (2) Women's Insole Version A; (3) Men's Insole Version B; and (4) Women's Insole Version B. Men's insole Version A and Women's Insole Version A use a softer foam than Men's Insole Version B; and Women's Insole Version B. Version A and Version B had the same physical dimensions, and were made from the same type of foam, albeit with a slightly different formulation, resulting in a OO hardness of approximately 47 for Version A and OO hardness of approximately 57 for Version B.
The study was designed as a two-cell, parallel group, one week use study to subjectively assess the degree of pain relief, comfort, and fit of two menus and two women's insoles. The evaluation was a balanced study among 20 men and 23 women ages 18-65 years old. Male subjects had shoe sizes of 8 to 13, and female subjects had shoe sizes of 6 to 10. Subjects agreed to wear their shoes with the insoles for a minimum of 8 hours/day for 5 days of a 7 day period. Subjects brought in two pairs of shoes to qualify for the study, and had to be willing to wear either socks or hosiery with the insoles during the test period.
Subjects were evaluated by a podiatrist to confirm that they had knee pain due to overpronation. To qualify for the study, the subjects had to have a minimum of a 2.5 on the VAS (visual analogue scale) knee pain scale. Qualified subjects initially evaluated their degree of knee pain (due to overpronation) on a VAS scale prior to insole assignment. Once they had received their insoles and placed them in their shoes, the subjects walked for a one minute period and then reassessed their knee pain on a VAS scale.
Subjects returned to the clinic 24 hours and seven days after baseline (Day 1). They wore their insoles for 8 hours before the 24 hour visit and they wore the insoles for a minimum of 8 hours a day for five of the seven days. Subjects used VAS scales to record the degree of knee pain. A subjective assessment of various attributes such as comfort and fit were gathered using a questionnaire. Subjects returned their insoles and their completed Daily Diaries before being released from the study.
Subjects self-assessed their degree of knee pain at baseline before using the insoles, then at one minute, 24 hours, and one week after receiving the insoles. In each evaluation, subjects had been on their feet for an 8 hour day. Subjects used a 10 centimeter VAS scale to rate pain, where 0=no pain and 10=the worst possible pain. Measured VAS evaluations were converted to numerical values. Mean changes from baseline were analyzed using a paired t-test. The mean values for the VAS ratings are summarized in table 1.
As can be noted in the table above, there were statistically significant reductions in pain for both versions of the insoles at 1 minute, 24 hours, and 1 week.
Several embodiments of the present invention are specifically described herein. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.
