Functional foot cover

A cover for a foot prosthesis comprises an opening at a top end of the cover, which extends into a cavity formed within the cover, wherein the cavity is configured to receive a prosthesis therein. A wall surrounds the cavity and has the shape of a natural human foot. The wall has an inner surface and an outer surface. The wall also has a top section, a bottom section and a rear section. The bottom section defines a sole area having a toe section, a heel section, and a metatarsal region, wherein the sole area is provided with varying levels of stiffness configured to induce a desired rollover from heel-to-toe in a lateral-to-medial direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to foot covers and, in particular, to covers for a foot prosthesis.

2. Description of the Related Art

Conventional prosthetic foot designs are sometimes enclosed in a cosmesis or cover to improve the aesthetic appeal of the prosthesis, as shown, for example, in U.S. Pat. No. 4,865,612 to Arbogast et al. Some conventional cosmesis designs have the shape of a human foot and are made, for example, of rubber or other flexible materials, which provide additional cushion to the prosthesis during use. However, conventional cosmeses are not designed enhance the performance of the prosthesis based on the nature and impact-level of the expected use.

Accordingly, there is a need for an improved foot cover that can be used in combination with a prosthesis to achieve a desired performance based on the impact-level of the expected use.

SUMMARY OF THE INVENTION

In accordance with one embodiment disclosed herein, a cover for a foot prosthesis is provided. An opening at a top end of the cover extends into a cavity formed within the cover, wherein the cavity is configured to receive a prosthesis therein. A wall surrounds the cavity and has the shape of a natural human foot. The wall has an inner surface and an outer surface. The wall also has a top section, a bottom section and a rear section. The bottom section defines a sole area having a toe section, a heel section, and a metatarsal region, wherein the sole area is provided with varying levels of stiffness configured to induce a desired rollover from heel-to-toe, a portion of the desired rollover being in a lateral-to-medial direction.

In accordance with another embodiment disclosed herein, a cover for a foot prosthesis is provided comprising an opening at a top end of the cover. The opening extends into a cavity within the cover configured to receive a prosthesis therein. A wall surrounds the cavity and has the shape of a natural human foot. The wall has an inner surface and an outer surface. The wall also has a top section, a bottom section and a rear section. The bottom section defines a sole area having a toe section, a heel section, and a metatarsal region, wherein the sole area is provided with a plurality of selected regions of differing stiffness relative to areas surrounding said selected regions.

In accordance with still another embodiment disclosed herein, a cover for a foot prosthesis is provided comprising an opening at a top end of the cover. The opening extends into a cavity within the cover configured to receive a prosthesis therein. A wall surrounds the cavity and has the shape of a natural human foot. The wall has an inner surface and an outer surface. The wall also has a top section, a bottom section and a rear section. The bottom section defines a sole area having a toe section, a heel section, and a metatarsal region, wherein the sole area is provided with at least one selected region of reduced stiffness relative to an area surrounding said selected region.

In accordance with yet another embodiment disclosed herein, a cover for a foot prosthesis is provided, the cover having the shape of a natural human foot. An opening at a top end of the cover extends into a cavity within the cover, the cavity configured to receive a prosthesis therein. A top section extends between the opening and a toe section. A rear section extends between the opening and a heel section. A bottom section defines a sole area between the heel section and the toe section, the sole area having a metatarsal region extending between an inner edge and an outer edge of the bottom section. A section of shock absorbing material is disposed on the sole area and has a first selected stiffness. The section of shock absorbing material is configured to provide a desired level of shock absorption. A section of energy return material is disposed on the sole area and has a second selected stiffness. The section of energy return material is configured to provide a desired level of energy return. The sections of shock absorbing material and energy return material effect a desired rollover during a transition from heel-strike to toe-off to approximate the rollover of a human foot.

In accordance with another embodiment disclosed herein, a cover for a foot prosthesis is provided, wherein the cover has the shape of a natural human foot. The cover comprises a bottom section that defines a heel section, a toe section, and a metatarsal region therebetween. A first material is disposed on the heel section and has a first selected stiffness. A second material is disposed on the metatarsal section and has a second selected stiffness different from the first selected stiffness, wherein the first and second materials induce a rollover during a transition from heel-strike to toe-off, a portion of the desired rollover being in a lateral-to-medial direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Foot covers are known in the art and are described, for example, in pending U.S. application Ser. No. 09/586,666, filed Jun. 1, 2000, the contents of which are incorporated herein by reference in their entirety.

FIG. 1illustrates one embodiment of a functional foot cover100. Preferably, the functional foot cover100has the shape of a natural human foot, including a heel section10and a toe section20. In one preferred embodiment, the functional foot cover100can be made of polyurethane or a similar material. However, the functional foot cover100can be made of other suitable materials, such as materials commonly used for the manufacture of prosthetic cosmeses.

FIG. 2Aillustrates a cross-section of another embodiment of a functional foot cover200. The functional foot cover200is preferably configured to receive a prosthesis therein, such as the prosthetic foot50illustrated inFIG. 2B. In the illustrated embodiment, the prosthetic foot50is an Elation™ Foot by Össur of Reykyavik, Iceland. However, the use of any of the functional foot cover embodiments disclosed herein is contemplated with any prosthetic foot design.

In the illustrated embodiment, the foot cover200has an opening212at a top end210thereof and a wall214having an inner surface216and an outer surface218. The inner surface216comprises a top section216a, a bottom section216band a rear section216cLikewise, the outer surface218comprises a top section218a, a bottom section218band a rear section218c. The opening212and inner surface216together define a cavity220within the functional foot cover200. Preferably, at least one recess230is formed on the inner surface216of the wall214. In the illustrated embodiment, a plurality of recesses230are shown, some of which are disposed on the bottom section216balong a metatarsal region240proximal a toe section250of the foot cover200. Recesses230can also be disposed on the rear216cand top216asections of the wall214. In another embodiment, the recesses230can be formed on the outer surface218of the foot cover200. Preferably, the recesses230are disposed on the foot cover200so as to facilitate flexion of the foot cover200during use. For example, when the foot cover200is placed on a prosthetic foot, the recesses230facilitate the flexion of the cover200during the prosthetic foot's walking motion, such as during toe-off. Accordingly, the recesses230advantageously provide a functional foot cover200with improved rollover characteristics. In one embodiment, the recesses230are notches230formed on the inner surface216of the wall214of the functional foot cover200, as illustrated inFIG. 2. In a preferred embodiment, the notches230extend between about ¼ and about ½ of a thickness214aof the wall214of the foot cover200. However, the notches230can have other depths, such as less than about ¼ of the thickness214aof the wall214, or more than about ½ of the thickness214aof the wall214, as desired.

FIG. 3illustrates a cross-sectional side view of another embodiment of a functional foot cover300. In the illustrated embodiment, a shock absorbing material330is preferably disposed in the heel section310of the foot cover300. For example, the shock absorbing material330can be inserts332disposed in cavities334formed on the inner surface316of the foot cover300. Preferably, the shock absorbing material330can be embedded into the heel section310. In another embodiment, the shock absorbing material330can be attached to the inner surface316of the foot cover300with, for example, an adhesive. In still another embodiment, the shock absorbing material330can be removably attached to the inner surface316of the foot cover300. For example, the shock absorbing material330can comprise inserts332that lockingly engage recesses or cavities (not shown) formed on the inner surface316of the foot cover300. As shown inFIG. 3, the shock absorbing material330is disposed on at least a portion of the heel section310. In a preferred embodiment, the shock absorbing material330covers an area between about 6 cm2and about 20 cm2of the heel section310. In other embodiments, the shock absorbing material330can cover an area of less than about 6 cm2. In still other embodiments, the shock absorbing material330can cover an area of more than about 20 cm2.

The shock absorbing material330is preferably disposed on areas of the foot cover300that receive high impact forces during use. In one embodiment, the shock absorbing material330is EVA, or a similar material. However, other materials providing suitable shock absorbing characteristics can also be used.

As illustrated inFIG. 3, an energy return material350is also disposed in the metatarsal area340proximal the toe section320of the foot cover300. In one embodiment, the energy return material350can comprise inserts352disposed in cavities354formed on the inner surface316of the foot cover300. Preferably, the energy return material350is embedded into the wall314of the foot cover300. In another embodiment, the energy return material350can be attached to the inner surface316of the foot cover300with, for example, an adhesive. In still another embodiment, the energy return material350is removably attached to the inner surface316of the foot cover300. In a preferred embodiment, the energy return material350covers at least a portion of the metatarsal region340of the foot cover300. For example, the energy return material350can comprise inserts352that lockingly engage recesses or cavities354formed on the inner surface316of the foot cover300. Preferably, the energy return material350covers an area of between about 6 cm2and about 20 cm2of the metatarsal region340of the foot cover300. In other embodiments, the energy return material350can cover areas less than about 6 cm2. In still other embodiments, the energy return material350can cover an area of more than about 20 cm2. Additionally, the energy return material350is an elastic material, such as silicone. However, other materials that provide suitable energy return characteristics can also be used.

FIG. 4illustrates another embodiment of a functional foot cover400. In the illustrated embodiment, the shock absorbing430and energy return450materials discussed above are attached to a bottom outside surface418bof the foot cover400. In one embodiment, the shock absorbing material430and energy return material450comprise inserts432,452removably disposed in cavities434,454formed on the bottom surface of the foot cover400, respectively. For example, the shock absorbing430and energy return450materials can be attached to the foot cover400with an adhesive. In another embodiment, the inserts432,452can have engagement members (not shown) that snap onto the recesses or cavities434,454. However, the shock absorbing430and energy return450materials can be attached to the foot cover400using other known mechanisms, such as bolts and screws. In another embodiment, the shock absorbing430and energy return450materials can be molded onto the foot cover400during manufacture.

In a preferred embodiment, a set of shock absorbing inserts432having varying levels of shock absorption are provided. Accordingly the foot cover400can be tailored to provide the level of shock absorption best suited for a particular user's needs. Similarly, a set of energy return inserts452with varying levels of energy return can be provided to provide the level of energy return required by a specific user. Accordingly, the shock absorption430and energy return450materials can be tailored to the particular activity level of the user. For example, for a low-activity user, the shock absorption material430can be a highly elastic material, such as a highly elastic urethane or other polymer material. Similarly, for a high activity user, the shock absorption material430can be one with a lower elasticity.

FIG. 5illustrates another embodiment of a functional foot cover500. In the illustrated embodiment, the foot cover500comprises materials of selected stiffness disposed along the sole area505of the foot cover500. For example, said materials can have a durometer of between about 60 Shore A and about 95 Shore A. However, in other embodiments, the materials can have other levels of stiffness. In the illustrated embodiment, said materials are injection molded onto the foot cover500during manufacture. As shown inFIG. 5, the heel section510comprises a first material530of selected stiffness. Additionally, at least a portion of the metatarsal region520comprises a second material532of selected stiffness, which can have the same stiffness as the material in the heel section510. Still another section525of the sole505of the foot cover500comprises a third material534of selected stiffness, which may be different than that of the heel510or metatarsal sections520. It will be obvious to one of ordinary skill in the art that various materials, each having a different stiffness, can be incorporated into the foot cover500. Moreover, though the illustrated embodiment illustrates three different areas comprising materials of selected stiffness, it will be obvious to one of ordinary skill in the art that more or fewer areas of selected stiffness can be incorporated into the foot cover500.

Preferably, said materials530,532,534are disposed, and their stiffness selected, so as to guide the rollover of the foot cover500during use. For example, material having a higher stiffness can be disposed on the heel section510and be surrounded by material of lower stiffness. In another embodiment, the material disposed on the heel section510of the foot cover500can have a lower stiffness than the material surrounding said heel section510. Similarly, the material disposed on the metatarsal region520can be disposed, and its stiffness selected, so as to guide the rollover of the foot cover500. In one embodiment, the material disposed on the metatarsal region520has a higher stiffness than the material surrounding said region. In another embodiment, the material disposed on the metatarsal region520has a lower stiffness than the surrounding material. In a preferred embodiment, the materials are disposed, and their stiffness selected, so that the functional foot cover500rolls over medially toward an inner edge540of the foot cover500during transition from heel-strike to toe-off and approximates the rollover of a natural human foot.

Preferably, the coverage area of each material of selected stiffness is chosen to adequately guide the rollover of the foot cover500, as described above. For example, the material disposed on the heel section510can have an area of between about 6 cm2and about 20 cm2. Similarly, the material of selected stiffness disposed on the metatarsal region520can have an area of between about 6 cm2and about 20 cm2. However, in other embodiments the material of selected stiffness can be have an area less or greater than that disclosed above.

FIG. 6illustrates another embodiment of a functional foot cover600. In the illustrated embodiment, the foot cover600includes a heel section insert630attached thereto and made of a material having a selected stiffness, which preferably differs from the stiffness of the surrounding area on the foot cover600. Similarly, the foot cover600includes a toe section insert640attached thereto and made of a material having a selected stiffness, which preferably differs from the stiffness of the surrounding area. Said materials preferably have a durometer of between about 60 Shore A and about 95 Shore A. In other embodiment, said materials can have other levels of stiffness. For example, the materials can have durometers lower or greater than the values noted above. Preferably, the heel and toe section inserts630,640are removably attached to the foot cover600. For example, the section inserts630,640can be lockingly snapped onto cavities632,642formed on the foot cover600. In another embodiment, the toe and heel section inserts630,640can be attached to the foot cover600with an adhesive. However, the section inserts630,640can be attached to the foot cover600using other fixation mechanisms, such as bolts and screws. Preferably, sets of inserts are provided, each having a different stiffness level. Accordingly, the foot cover600can be tailored to have a particular rollover characteristic based on the stiffness level of the toe and heel section inserts630,640that are attached to the toe section620and heel section610, respectively, of the foot cover. Moreover, as discussed above, the inserts630,640can be tailored to the particular activity level of the user.

FIG. 7illustrates another embodiment of a functional foot cover700. In the illustrated embodiment, a sole portion720extending between a heel section722and a toe section724, and defining a metatarsal region726therebetween, is provided for attachment to the foot cover700. The sole portion720has areas725of selected stiffness with a durometer preferably between about 60 Shore A and about 95 Shore A. In other embodiments, said areas725can have a durometer higher than about 95 Shore A. In still other embodiments, said areas725can have a durometer lower than about 60 Shore A. In the illustrated embodiment, the sole portion720has an opening727adisposed generally at the heel section722and a second opening727bdisposed generally at the metatarsal region726. The openings727a,727bare preferably configured to fit over inserts of selected stiffness732,734located generally at a heel section and metatarsal region of the foot cover700, respectively. In one embodiment, the inserts732,734have a stiffness level different than the stiffness of the surrounding area725on the sole portion720. One of ordinary skill in the art will recognize that the sole portion720can have any number of openings configured to accommodate an equal number of inserts of selected stiffness disposed in the foot cover700. In another embodiment, the sole portion720does not have any openings.

In one embodiment, the sole portion720is removably attached to the foot cover700. For example, the sole portion720can have members (not shown) that protrude into recesses or cavities (not shown) formed on the bottom of the foot cover700so as to lockingly engage the sole portion720to the foot cover700. In another embodiment, the sole portion720can be attached to the foot cover700with an adhesive. As with the embodiments illustrated inFIGS. 5 and 6, the sole portion700can be manufactured using materials of different stiffness to guide the rollover of the foot cover700during use. In a preferred embodiment, said guided rollover is used to control pronation of the foot cover700during use. More preferably, the guided rollover approximates the walking motion of a natural human foot, so that the foot cover700rolls over medially toward the inner edge740of the foot cover700during transition from heel-strike and toe-off. One of ordinary skill in the art will recognize that the guided rollover characteristics described above can be incorporated into the sole portion720of a cosmesis as described above, as well as an individual sole attached to a prosthetic foot, as described in U.S. Provisional Application No. 60/575,142, filed May 28, 2004, which is incorporated herein by reference in its entirety.

The foot cover700preferably comprises a metatarsal region750generally parallel to a supporting surface on which the foot cover700rests. Additionally, the toe section760of the foot cover700preferably comprises a set of toes765having an upper bend or tilt to provide a smoother toe push-off during use.

FIG. 8Aillustrates another embodiment of a functional foot cover800with a support member820disposed therein. In the illustrated embodiment, the support member820is a plate that is preferably embedded in the wall824of the foot cover800. The support member820is preferably made of a stiff material. For example, the support member820can be made of a carbon fiber material. However, the support member820can be made of other suitable materials that provide the desired stiffness, such as a hard plastic. Advantageously, the support member820improves the stability of the foot cover800along the metatarsal region840. In one embodiment, the support member820extends along a portion of the metatarsal region840. In another preferred embodiment, the support member820attaches to the bottom of the foot cover800and extends transversely across substantially the entire width W of the foot cover800at the metatarsal region840, as illustrated inFIG. 8B. In other embodiments, the support member820can have other shapes, such as cylindrical. Additionally, the support member820can be disposed on other areas of the foot cover800requiring additional stability.

FIGS. 9A and 9Billustrate another embodiment of a functional foot cover900. In the illustrated embodiment, the foot cover900includes a heel section910having a material of a selected stiffness920. Preferably, said material of selected stiffness920is disposed on the heel section910of the foot cover900so as to improve the stability of the foot during heel strike. In the illustrated embodiment, the material of selected stiffness920is embedded into the heel section910so that the medial912and lateral914edges of the heel are stiffer than the middle portion916of the heel. Preferably, said material of selected stiffness920is injection molded into the heel section910during manufacture of the foot cover900. In another embodiment, said materials of selected stiffness920can be removably attached to the heel section, via for example, snap-on inserts, as discussed above.

FIGS. 10A and 10Billustrate another embodiment of a functional foot cover1000. In the illustrated embodiment, the foot cover1000comprises the shell1100configured to fit over a prosthetic foot or other prosthetic device. In one preferred embodiment, the shell1100is sized to fit within conventional footwear, such as a shoe. More preferably, the shell1100is sized to substantially completely fill the inside of a shoe. As illustrated inFIG. 10B, the shell1100comprises a top surface1110and a side surface1120, but does not have a bottom surface.

With reference toFIG. 11A, another embodiment of a functional foot cover1200is disclosed. In the illustrated embodiment, the top portion1210of the foot cover1200proximal an opening1220includes a surface of increased area1230to facilitate the attachment of foam or other cosmetic filling to the functional foot cover1200. As shown inFIG. 11, the surface of increased area1230includes several slots1232to facilitate attachment of the functional foot cover1200to foam or other cosmetic filling. One of ordinary skill in the art will recognize that the number of slots1232on said foot cover1200can vary so as to be fewer or more than those depicted inFIG. 11A.

FIG. 11Billustrates another embodiment of a functional foot cover1300having a surface of increased area1330on a top portion1320of the foot cover1300. In the illustrated embodiment, the surface of increased area1330defines a recess1332proximal a heel section1310of the foot cover1300. Said recess1332is preferably sized so as to facilitate attachment of the foot cover1300to foam or other cosmetic filling.

FIG. 12illustrates another embodiment of a functional foot cover1400. In the illustrated embodiment, a height H of the foot cover1400is generally higher than conventional foot covers. For example, the height H of the foot cover1400can be between about 7 cm and about 10 cm. In other embodiments, the height H of the foot cover1400can be greater than about 10 cm. Preferably, a wall1430of the foot cover1400has a thickness T that tapers from a thicker section at the bottom1410of the foot cover1400toward a thinner section proximal an opening1425at a top end1420of the foot cover1400. In another embodiment, the wall1430of the foot cover1400has a stepped thickness T, with a thicker section proximal the bottom1410of the foot cover1400and a thinner section proximal the top end1420of the foot cover1400. Preferably, the thickness T of the wall1430at the opening1425of the foot cover1400is between about ¼ and about ½ the thickness T of the wall1425proximal the bottom1410of the foot cover1400. In other embodiments, the thickness T of the wall1430at the opening1425of the foot cover1400can be between about ⅛ and about ¾ of the thickness T of the wall1430proximal the bottom1410of the foot cover1400. Said tapered thickness T advantageously facilitates the insertion of a prosthetic device within the foot cover1400.

FIGS. 13A and 13Billustrate another embodiment of a functional foot cover1500. In the illustrated embodiment, a sole1510of the foot cover1500includes areas of non-slip material1530. Preferably, said areas of non-slip material1530increase the traction of the foot cover1500during slippery conditions, such as on a wet surface. In one embodiment, said areas of non-slip material1530include a pattern designed to increase traction of the foot cover1500during use. Preferably, the areas of non-slip material1530are molded to the sole1510of the foot cover1530during manufacture. In another embodiment, the areas of non-slip material1530can be applied to the bottom1510of the functional foot cover1500. For example, the non-slip material1530can be sprayed onto the bottom1510of the foot cover1500. In a preferred embodiment, the non-slip material1530comprises silicone. However, other materials having suitable non-slip characteristics can be used. In one embodiment, the non-slip material1530is applied to substantially the entire sole1510of the foot cover1530. In another embodiment, the non-slip material1530is applied to selected localized areas on the sole1510of the foot cover1500.

With respect to any of the embodiments described above, the functional foot cover can be manufactured to resemble a human foot, both male and female, and have five toes. In one embodiment, the foot cover can be used with a sandal. For example, as illustrated inFIG. 5, among other figures, the foot cover500can have a slot550between at least two of the toes552,554formed on the foot cover500, said slot550configured to receive a strap of a sandal. In another embodiment, the foot cover defines several toes disposed adjacent each other without any intervening slots therebetween.

Additionally, any of the embodiments discussed above can be manufactured so as to closely resemble the person's foot. In one embodiment, a person's foot is scanned and a mold of said foot manufactured based on said scanning. Preferably, foot covers of varying sizes are manufactured using said foot scan. Advantageously, construction of a foot cover using a mold based on a scanned foot provides a more accurate anatomical representation of a natural human foot.

Of course, the foregoing description is that of certain features, aspects and advantages of the present invention to which various changes and modifications can be made without departing from the spirit and scope of the present invention. Moreover, the functional foot cover may not feature all objects and advantages discussed above to use certain features, aspects and advantages of the present invention. Thus, for example, those skill in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition, while a number of variations of the invention have been shown and described in detail, other modifications and methods of use, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is contemplated that various combinations or subcombinations of these specific features and aspects of embodiments may be made and still following the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed functional foot cover.