US20150181978A1

US20150181978A1 - Foot Membrane

Info

Publication number: US20150181978A1
Application number: US14/657,614
Authority: US
Inventors: Sharone Piontkowski
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-09-28
Filing date: 2015-03-13
Publication date: 2015-07-02

Abstract

The present invention is a non-woven foot membrane that helps provide comfort and support for the foot during high-heel or regular shoe wear. The device comprises a self-supporting membrane that flexes, stretches and conforms to the shape of the foot, or the portion of the foot in contact with the membrane, when worn. The device has different thicknesses throughout its structure. Preferably, the parts of the invention at and around the major points of contact on the bottom of the foot when wearing a shoe such as a high-heel, that is, the parts of the invention under the big toe, metatarsal heads of the forefoot, and the heel, are thicker than the other portions of the device. The device also has different frictional properties at the inner/upper surface and outer/lower surface as well as a curvilinear form that each work to cup and grip the foot as well as prevent slippage in the shoe. The increased thicknesses throughout various parts of the structure of the device as well as the opposing frictional properties and curvilinear shape all work to counteract the stresses experienced by the plantar soft-tissue during shoe wear.

Description

CROSS REFERENCE TO RELATED APPLICATION

This non-provisional utility patent application is a continuation-in-part of application Ser. No. 13/630,993, filed on Sep. 28, 2012, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/626,541, filed on Sep. 28, 2011, each, which is expressly incorporated herein in its entirety by reference thereto.

FIELD OF THE INVENTION

The invention relates to the field of foot orthotics, shoe inserts, foot insoles, cushioning pads, and protective garments for the foot in the form of hosiery, socks, self-adhering membranes, and shoe inserts. The invention relates to foot care products that improve shoe comfort, skin protection, and provide performance enhancement. The invention also relates to gelatenous materials and high performance polymer-based textiles/materials and the processes used to fabricate such materials. The invention relates to silicone materials, including a single layered silicone material having different coefficients of friction on opposing surfaces as well as dual or multilayer silicone materials where each layer may have a thicknesses, durometer, and/or tackiness property (coefficient of friction) different than another layer(s). The invention also relates to thermoplastic membranes, polymer (polyurethane) films, extruded polyurethane extruded films, thermoplastic membrane sheets, and the processes and methods used to make such materials.

BACKGROUND OF THE INVENTION

The adverse biomechanical changes that occur on a foot positioned in a high-heeled shoe have been studied and discussed. Adverse effects of high-heel shoe wear are commonly experienced by people, typically women, in the form of general pain and discomfort and more prevalent foot problems. Regular high-heeled shoe wear is a known cause to common foot problems such as, for example, skin irritation, blisters, skin stiffening, calluses, plantar forefoot pain at the forefoot, and metatarsalgia. A study by Damson et. al. (2002) reports eighty three percent (83%) of foot problems are seen in women ages 50-70 who regularly wear high-heeled shoes. It has been recommended that women not wear a heel height greater than 5 cm (about 2 inches), yet most fashionable high-heeled shoes are higher than this figure (Ebbeling et. al., 1994). Despite the pain experienced by women, the desire to be fashionable and look professional leaves the high-heeled shoe a commonplace shoe choice. It has been reported that 59% of women wear high-heeled shoes between one to eight hours a day (Gallop Org., 1986).
Several studies show that when high-heeled shoes are worn, the biomechanics of the foot changes such that the heel is raised, the toes are dorsiflexed as in the “push off” phase of the Gait cycle, the arch of the foot raises upwards, the length of the foot decreases and the foot is likely to rotate or pronate inwards (Cowley et al, 2009). The biomechanical changes that occur are known to cause the weight of the body to shift from the heel and lateral forefoot towards the central and medial forefoot, with significant increased pressure at the first and second metatarsal heads of the medial forefoot (Mandato and Nester, 1999; Speksnijder et al., 2005; Soames and Clark, 1985). It has been shown that medial forefoot pressure increases significantly the higher the heel height (Mandato and Nester, 1999; Speksnijder et al., 2005). It has also been shown that during walking, the increased pressure at the medial forefoot shifts entirely to the hallux (big toe) with a heel height higher than 3 cm (Mandato and Nester, 1999).
Most scientific studies that examine the adverse effects of the high-heeled shoe take pressure measurement readings at the external plantar surface, while the internal stress/strains of the subcutaneous plantar soft tissue (“ST”) beneath the plantar surface during high-heeled shoe wear was not well known and described until recently.
Recent studies that use sophisticated computational finite element modeling or ultrasound technology have shed light on the complex biomechanical behavior and stress/strain of the internal plantar ST and its relationship to the external pressure measurements taken at the plantar surface of the foot during high-heel shoe wear (Yu et al., 2007; Ko et al., 2009). A study by Yu et al. (2007) that uses a finite element model of the foot in a high-heeled shoe shows that while, as expected, there was an increase in von Mises stress at the first metatarsal head, there was a decrease in the strain at the plantar fascia that works to support the medial foot arch. This shows that high-heeled shoes can help alleviate the strain of the fascia/soft tissue under the medial foot arch and indicates that an arch support is less important during high-heeled shoe wear.
A study by Ko et. al. (2009) that looks at the relationship between plantar pressure and ST strain under the metatarsal heads of the forefoot when wearing different height high-heeled shoes shows that while, as expected, metatarsal pressure significantly increased and shifted to the first and second metatarsal heads with increasing heel heights, the ST strain under the metatarsal heads plateau after a heel height of 2 cm, showing that the plantar ST reaches a state of maximum compressibility at heel heights a little less than about 2 cm (1 inch). Typical heel heights range from 2-4 inches and some high-heels are 5 inches or more. The study shows that while pressure at the forefoot increases with a higher heeled shoe, the natural plantar ST padding ability has already “bottomed out” or reached its maximum cushioning ability in any high-heeled shoe over 2 cm. The study suggests that the ST reaches maximum compressibility because the ST under the forefoot is already experiencing tensile loading when the foot is positioned in a high-heeled shoe such that the heel is elevated, the toes are dorsiflexed, and the medial arch raises which, in turn, stretch out the plantar ST that runs along the longitudinal axis of the foot. The Ko et. al. study concludes that the force that the ST endures at a state of maximum compressibility cannot be properly distributed by the natural plantar ST cushioning systems of the foot and can possibly lead to internal, plantar ST strain and damage.
Another recent study by Chen et al. (2010) that uses a finite element model of the foot placed on a flat contact surface shows a large von Mises stress occurs at the medial forefoot at areas where the plantar ST contacts the geometrically irregular bony prominences of the metatarsal heads. The study also shows that the internal plantar ST displacement is highest between the fourth and fifth metatarsal heads where the ST is oriented against the oblique bone edges. The study speculates that this may lead to increased shear stresses and may explain why the ST is known to shift a small distance at the area during pressure readings. Thus, the shear displacement of the plantar ST between the fourth and fifth metatarsal heads may lead to the callused skin typically found at a women's lateral forefoot and while the reduction of pressure forces are the main concern for the comfort of the medial forefoot, the lateral forefoot at the fourth and fifth metatarsal heads could be more vulnerable to increased shear forces.
Shoe inserts are commonly known foot care products used to try to alleviate the problem of foot discomfort during shoe wear. More specifically for people that wear high-heeled shoes, shoe inserts are intended to counteract the increased medial forefoot pressure and foot pain experienced during shoe wear.
Shoe inserts are made from different shaped and sized materials designed to have bordered edges that match the general outline of the foot sole and inner shoe sole perimeter. Shoe inserts are a mass of material that is placed or adhered into the shoe body to lie flat and stationary on top of the inner sole of the shoe. Commonly known shoe inserts include basic flat full insoles, molded foot orthotics/total contact inserts (TCI), heel inserts/cushions, arch supports and ball-of-the-foot pads. Shoe inserts can also be custom made to fit an individual's foot shape in the form of a custom made foot orthotic, also known as a Custom Made Insole (CMI).
A full insole shoe insert, such as a basic insole or foot orthotic/TCI/CMI, is typically sized and shaped to cover the entire length of the inner sole and provide cushioning along the entire foot, while a heel insert/cushion, arch support, and ball-of-the footpad are of smaller shapes and sizes that target specific parts of the foot known to experience pain or discomfort during shoe wear. To provide added comfort during high-heeled shoe wear, people often use a flat shoe insert such as a ball-of-the-foot pad or basic flat insole that extends from the forefoot to the heel without protection given to the big toe (as opposed to a foot orthotic/TCI/CMI). Basic off-the-shelf flat shoe inserts have generic sizes, shapes and uniform thicknesses.
Hosiery garments are another type of product used to try to alleviate foot discomfort during shoe wear. Hosiery garments worn on the foot and leg, such as sheer pantyhose, nylons, tights, stockings, and thin socks are used during high-heeled shoe wear. Sheer/opaque stockings, tights, pantyhose, nylons, etc. are typically worn with a high-heeled pump, a strappy sandal, a shoe boot, etc., that leaves part of the foot and/or leg exposed when worn with clothing. A thin woven sock is also sometimes used for high-heeled shoe types that cover the foot body and leg such as a mid-calf or knee-high high-heel boot. The general function of these various hosiery types is to hide any physical imperfections on the legs or feet, provide a basic level of shaping and support to the leg, keep the legs and feet warm, and ease chafing between the foot and footwear. These hosiery products are typically woven in a tubular shaped form from nylon and/or spandex to have a stretchy, close fitting, form that covers the foot and leg and are thin and elegant enough to wear with high-heeled shoes. The hosiery can be worn as an undergarment but are more commonly worn as an under/outer garment that is partially exposed when wearing a skirt/dress or pants. Hosiery products come in different colors and styles and are worn as a fashion item.
Socks are yet another type of product used during shoe wear to help with comfort. A sock is woven from a variety of fiber thicknesses and materials such as cotton, wool, cashmere, acrylic, polyester, etc. into a general tubular form and is seemed at the toes. Woven socks can also have lycra/spandex added to the fiber blend to make the sock more stretchable and form fitting. Thinly woven socks are commonly worn with a closed-body high-heeled shoe type such as shoe boot/ankle boot. Thin socks are not typically used with a high-heeled shoe that exposes part of the foot body such as a basic pump or strappy sandal as it would detract from the look of the shoe, which is intended to show the natural foot form.
Athletic socks, usually intended for use with sportier shoe types, are typically made from absorbent woven cotton, wool or acrylic to absorb moisture and cushion the foot for added comfort. Specialty athletic socks can be enhanced on the insole portion of the sock with a more densely woven and/or thick fiber structure for added cushioning. Some specialty athletic socks remain thinner at the foot body and have a more densely woven, fiber structure only at the heel and forefoot providing a thicker sock with added padding at those locations. Special athletic socks can also use low-friction fibers/finishes to decrease friction and/or wick moisture away from the foot's skin. Athletic socks provide performance features not found in hosiery but are too bulky, thick, and opaque to be a viable, functional solution for use with a form-fitting high-heeled shoe.
Foot covers, liners, and toe covers can also be used during shoe wear to help with comfort and protection. Foot covers, liners, and toe covers are made to protect the foot just like any other form of hosiery, but are shaped to cover the minimal amount of the foot to provide protection only to select areas of the foot in contact with the shoe body. Foot covers come in a variety of shapes and are typically made of a known, basic hosiery material such as nylon, spandex, and/or cotton. The shape of a basic foot cover, or “peds” as they are known, is much like that of a ballet slipper; it is not as full as a sock or stocking with the cover just extending over the front of the toes to the back of the heel to cover the underside of the plantar foot. The foot cover shape is intended to remain hidden under the shoe body such that the upper foot and leg are bare and it appears that one is not wearing a hosiery item. Foot liners are appropriate for use with dressier shoes such as a high-heeled pump or during warm weather when a sock/tight or pantyhose is undesirable. Foot liners and covers are not typically woven in a circular tubular form like a sock but are rather cut out from a flat fabric woven nylon/cotton/spandex material that is seemed together to make a basic foot shaped covering.
Some hosiery items, e.g., foot covers, liners, toe covers, come enhanced with a footpad at the ball of the foot. HUE and KUSHYFOOT brand products, for example, provide nylon foot liners/covers with an added pad at the forefoot. There is also a KUSHYFOOT product with hosiery material at the sole of the foot stitched in a texturized zigzag pattern that rubs against the foot to “massage” the foot during movement.
Other cushioned hosiery products that are available for use are gel-lined socks that are commonly sold and used for therapeutic purposes and for the treatment of the diabetic foot. Gel-lined socks are made from woven textile materials having gel linings or inserts with a uniform thickness, typically covering the entire insole.
A strong need exists for an alternative new type of foot care product that alleviates the common pain, discomfort, and skin irritations that occur during high-heeled shoe wear while working with the morphological makeup and biomechanical behavior of the foot in a high-heeled shoe. There is a need for a new type of product that simultaneously replaces the need for, and offers advantages to, both the traditionally known shoe insert and the traditionally known hosiery garment. There is a strong need for a product that is of optimized, conforming, biomorphic, thin, light-weight shape, and utilizes silicone materials and/or new types of breathable membrane films/moist gels/polymers that resemble and integrate with the morphology and biomechanics of the foot and plantar ST padding to become a working “second skin” or pseudo plantar ST layer and offers a truly bare look thus eliminating the need for traditionally known shoe inserts and hosiery items; a product that enables the foot to perform closest to its natural state as an enhanced version of itself.
There is currently not one product known that will act as both a cushioned insole system and protective garment continuously and progressively, grips, flexes, and conforms directly to and with the foot body and plantar ST of the motioned foot in a high-heeled shoe at all positions and moments in time.
While there are some commercial uses of polymer-based membrane/film products existing for transparent medical wound dressings, none of those products are utilized for footwear products nor are they readily adaptable for use as footwear products. For example, JOHNSON & JOHNSON's BIOCLUSIVE product and 3M's TEGADERM product are polyurethane foil, transparent dressings. These products provide a thin flat sheet, membrane/film with an adhesive backing that is adhered onto the skin to provide a barrier from outside contaminants and to protect and help heal skin lacerations, wounds, abrasions, ulcers, or burns. The film material is known to be “semi-occlusive” to allow for moisture vapor/oxygen exchange, to be breathable, and to permit the normal functioning of the skin, yet waterproof and impermeable to water/a water droplet so that the skin is left dry when exposed to liquids, showering etc. The film is intended to keep the skin at an optimal moisture level for enhanced skin healing. The membrane film can be worn for extended periods of time, typically up to seven days. The membrane film is a thin sheet of uniform thickness that can conform to the body shape and flexes with the skin. The product comes in a variety of sizes and is individually packaged on a paper backing that is then removed when the film is applied on the skin.
Wound dressings that use a transparent membrane/polyurethane film are also available with an added absorbent pad. For example, 3M's TEGADERM Absorbent Clear Acrylic Dressing layers an acrylic polymer pad between two layers of the transparent dressing. TEGADERM Thin Hydrocolloid combines the transparent film with a hydrocolloid that contains gel-forming agents that can adhere to moist and dry skin. The hydrocolloid absorbs wound exudate liquid and forms a gel that becomes progressively more permeable to allow the dressing to continue to cope with wound exudate.
SKINTEGRITY is another brand of wound dressing with a hydrogel that is hydrophilic and primarily composed of water to create a moist environment that cushions and protects the skin.
Other known uses of polymer-based membrane films include explorations in laboratory settings by MIT Department of Aeronautics and Astronautics. The U.S. Army Natick Soldier Center made an electrospun polyethylene nanofiber mat in the shape of a facemask in 2005. This was made in a laboratory setting and shown in an exhibition called ‘Extreme textiles’ at the Copper Hewitt Museum in NYC. The mask could be used for filtration and protection as a, second, breathable skin during biochemical warfare. MIT Department of Aeronautics also experimented with a hand-held apparatus that directly sprays an electrospun clear, skin onto a human hand as a custom, form-fitting, protective glove.
Notwithstanding the foregoing, there is no known product that uses a non-woven, breathable, textile/membrane of any type of composition (polymer-based, cotton, nylon, etc.) as the singular, primary, protective garment textile/material. Some woven fabrics are treated with a film coating of nanofibers (nano-treated) but these products remain to be woven textiles. For example, NANOGLIDE makes fabrics and fibers that incorporate polytetrafluoroethylene PTFE (Patented Fiber Technology) nano particles into fibers that are then woven into a textile used to make socks for possible use for outerwear and lining applications. The fabric purportedly has enhanced performance features that control sweat/moisture, abrasion and friction. There are also other sock products that use silver nano-particles to protect against odor and bacteria. Nanofibers also have the potential to be used as a protective film when applied onto an existing woven fabric. Research for use of nanofibers as both a protective coating/layer on an existing woven fabric and to create different fibers and coatings to make three-dimensional, non-woven clothing garments was also done at the U.S. Army Natick Soldier Center by electrospinlacing.
Currently known production processes for nanofibers include a process called electrospinning. Electrospinning uses an electrical charge to draw out very fine fibers (typically on the micro or nano scale) from a liquid. It is typically used to make fibers from a polymer-base solution. Use of electrospinning nanofibers has been widely seen in laboratory settings with the use of a basic set-up that consists of a single nozzle/cone/needle that draws fibers onto a flat collector sheet, grounded molded form, or rotating cylinder collector. Production of nanofibers in a basic laboratory setting with a single nozzle/needle is slow and the materials/membranes made are often non-uniform. Laboratories that use a single nozzle/needle do experimental tests on nanofiber orientation, fiber diameter and porosity for a wide range of application in several fields. Several companies/institutions are trying to develop technologies to make nanofibers at a faster, more efficient rate with greater control and uniformity. For instance, FIBERIO is developing a “forcespinning” technology and the Harvard School of Engineering has developed a rotary jet-spinning process to make nanofibers. NANOSTATICS uses a nozzle-based technique with multiple nozzles for larger scale nanofiber production. ELMARCO, the first known manufacturer of commercial industrially scalable machines for nanofibers uses a “nanospider” technology using a needle-free electrospinning process instead of using spinning nozzles to make flat sheet nanofiber materials. The Elmarco machines currently use the “nanospider” technology to spray fine fibers back and forth, much like a printer machine onto a continuous rotating substrate sheet that collects the material over time.
The current technologies, machines, and processes for making nanofibers are unproven and significantly, none have yet to be applied to the commercial textile industry in a cost-efficient, time-effective manner. None of the existing technologies provide for a durable, light-weight, non-woven nanofiber textile for wide spread use as a stand-alone, three dimensional, nanofiber textile material and/or as a protective three dimensional coating on an existing woven fabric or fiber. None of the existing technologies are proven for use in making nanofiber materials/membranes in 3D form.
Similarly, none of the existing technologies for polymer-based membranes provide for a durable, lightweight, non-woven textile for use as a stand-alone, three-dimensional, self-supporting membrane.
The novel form, structure, and process of making the disclosed invention is such that the invention provides both a full insole, foot integrated, cushioning system and a high performance protective hosiery membrane for the foot but is not recognizable and classifiable in its form, structure, function and way of making as a traditionally known shoe insert, cushion, sock, or hosiery item. The novel invention is intended for everyday use as both a cushioned protective hosiery garment and a foot integrated, cushioning insole system to replace the commonly known hosiery items and shoe inserts currently used for high-heeled shoe wear. The invention could be a durable and reusable hosiery membrane like the conventionally known hosiery items used with the high-heeled shoe or it could be an adhesive type membrane product. The novel invention can be hand washed for continual reuse (a special cleaning formula may be formulated to clean, sterilize and even re-invigorate the product).

SUMMARY OF THE INVENTION

The present invention is a non-woven, substantially transparent, foot membrane device that helps provide comfort and support for the foot. The present invention is primarily directed towards use with high-heeled shoes, but its use is not so limited and also includes uses with other footwear including regular shoes and sneakers.
The device according to the present invention is self-supporting in that it substantially maintains its form on its own, e.g., when not worn on the foot or placed in a shoe or sneaker. The device is comprised of material that flexes, stretches and conforms to the shape of the foot, or the portion of the foot in contact with the device, when worn.
The device according to one embodiment of the present invention has a base/primary membrane that forms its primary structure with a minimal thickness to decrease its visibility when worn. Preferably, the base/primary membrane is between about 1 to 20 mils thick. More preferably, the base/primary membrane is between about 1 to 6 mils. In addition to the membrane, the device includes increased thicknesses throughout various parts of its structure to counteract the stresses experienced by the wearer of a high-heeled shoe. The parts of the invention at and around the major points of contact on the bottom of a foot at the plantar soft tissue when wearing a shoe are thicker than the other portions of the membrane which are the parts of the invention under the mid-foot plantar surface (arch), the toes (except the big toe), and the upper foot/ankle. Those thinner portions of the device are preferably comprised of a single layer of membrane material. The membrane material can be a thermoplastic polyurethane (TPU), or other materials of comparable performance and physical characteristics including a small thickness. The parts of the device under and around the forefoot/metatarsals, the big toe, and the heel, are comprised of one or more layers of membrane material and have greater total thickness than the remaining parts of the device.
Preferably, for the thicker portions of the invention, the membrane has connected to it at least one layer of gel-like material, e.g., a polymer-base gel, such as a viscoelastic polyurethane gel or silicone. The gel-like material can be positioned on top of the membrane material and/or sandwiched between a plurality of membrane layers. In one embodiment, the gel-like layer of material is positioned on top of (attached to the top) of the membrane material such that the gel-like material is in direct contact with the skin when worn.
The gel-like layer acts like a cushion helping to absorb forces and reduce stress and strain on the foot. For example, the gel-like material conforms to the protruding shapes of the metatarsal heads of the foot when weight is placed on the toes. When the gel-like layer is positioned such that it is in direct contact with skin, it is preferable to use a softer, more conformable, gel-like material. For gel-like material layers not in direct contact with the skin, the same softer gel-like material can be used or a harder and more durable gel-like material can be used.
Preferably, the gel-like material comprises a polymer-based, viscoelastic, gelatinous material. The gel-like material is soft, yet substantially non-compressible, and conformable (molds around) to the surrounding areas of the plantar surface of the foot when force is applied without reducing in thickness to the point that all of its cushioning ability is lost (bottoming out). The gel-like material according to the invention may be a moist and/or self-adhering (e.g., sticky) polymer, such as a hydrogel, or naturally sticky silicone for providing a soothing feeling to the skin when in contact. The gel-like material can also be hydrophilic or have a hydrophilic coating so it can absorb water and perspiration during wear.
The present invention may be made in the form of a sock, a ped foot liner shape, a stick-on self adhering membrane covering only certain parts of the foot, shoe insert, shoe liner, and/or sock liner for a shoe. When in sock form and/or a self-adhering form of less than an entire foot covering, the device transitions from a single, thin, layer of membrane at the bordered edges (e.g., above the ankle) and also at the thinner portions of the device having a single membrane layer only (e.g., 1-20 mil), up to anywhere between about 1 to 4.5 millimeters (mm) under the toe areas of the device beneath where the big toe will be, at the front of the device beneath where the forefoot (metatarsal heads of the foot) will be, and the back portion of the device (more specifically under a heel portion) under where the heel will be. It being understood that alternative embodiments of the invention include other thicknesses at the bordered edges and the other thinner (single membrane layer) portions of the device, such embodiments possibly worn with high-heeled shoes and/or with regular shoe wear or with sport/athletic shoes as an athletic liner during activities. It is desirable to keep the thickness of the device at the borders and at the thinnest portions of the membrane as thin as possible so as not to be visible/detected when worn, particularly where the device ends on the foot, the ankle or the leg.
For those portions of the device including gel-like material, the greatest thickness of the device is preferably between about 1 to 2 millimeters (mm) at the heel portion, between about 1.5 and 4.5 mm at the front portion under where the metatarsal heads will be when the device is worn, and between about 1.5 and 2.5 mm at the toe portion of the device where the big toe will be when the device is worn. The device is configured to have the areas with increased thicknesses at the points of most impact of the foot when the device is worn in a shoe, namely, under the toe portion at the location of the big toe, under each of the metatarsal heads (particularly the first, second and third metatarsal heads), and under the heel, with a tapering to thinner thicknesses away from those points of most impact.
The foregoing thicknesses at those portions of the device under the points of most impact on the plantar surface, which include the gel-like material, can be attained with the use of one or more layers of the membrane and/or with one or more layers of gel-like material. For example, the membrane at the heel portion of the device could be comprised of one layer of gel-like material sandwiched between two membrane layers or on top of one membrane layer. Alternatively, the membrane at the heel portion could be comprised of two or more sandwiched layers of gel-like material (each positioned between layers of membrane) combined or layered together. Even further, the membrane at the heel portion could be comprised of two or more layers of gel-like material each gel-like layer having a membrane layer beneath it.
Preferably, each gel-like layer subtly increases in thickness inward from its outer perimeter such that it is of a nominal thickness at the bordered edges and thicker in the middle region creating a gradual, sloped, tapered, transition away from the areas of the device with the added cushioning to those without added cushioning.
The membrane that makes up the primary structure of the device works in tension when the foot's own natural ST is tensioned. The membrane could be, for example, a TPU membrane. The layers of the gel-like material that are supported on a membrane layer and/or pocketed between layers of membrane work in compressive resistance to pad the foot. The membrane layer(s) that support each gel-like layer support, conform, and stretch the gel-like layer over the plantar surface and foot skin when the device is worn and the foot is placed in an elevated position in a shoe. This ensures that the gel-like layers at the “cushioned areas” with gel-like material will continuously grip onto and maintain direct contact with the plantar surface contours allowing the gel-like layers to integrate, deform, stretch, and alter, with the natural plantar ST.
The portions of the device having a single layer of membrane without any gel-like layer(s) at the middle portion of the device work in tension to support and conform in shape to the mid-foot arch. This allows the membrane to maintain direct conformity to the mid-foot even with the various changing increases in arch height that occur when the foot is placed in high-heeled shoes with different heel heights and foot bed designs. Toes, when the device is worn, will be in contact with the membrane and have a gripping ability similar to a bare foot, which will likely improve stability and give a natural/bare feeling to the foot.
The innermost surface of the membrane (the inside/interior surface) in direct contact with the skin on the foot when the device is worn has a low coefficient of friction (preferably about 0.5 or less). The innermost surface will likely be of a low coefficient of friction due to the natural material properties of the membrane material used. For example, TPU film typically has an inherently low coefficient of friction. If necessary, or desired, lubricants/additives or a PTFE coating can be used/added in a spray coating or by being impeded into the material itself to achieve the desired coefficient of friction. Alternatively, the inner surface could be coated with a viscoelastic gel having a low friction coefficient to attain this characteristic.
The entire outermost surface (outside/exterior surface), e.g., the exterior of the sock for an embodiment in sock form or the surface placed in contact with the upper surface of the insole of the footwear, has a higher coefficient of friction value, preferably 0.5 or above. Alternatively, only portions of the outermost surface, e.g., the parts of the device under the points of most impact when worn (under the heel portion, under the front portion, and/or under the toe portion), can have the higher friction surface than the remaining areas of the exterior/outer surface of the device. Even further, the entire bottom of the membrane's exterior/outer surface can be made with materials having the higher friction surface properties than the remainder of the membrane. Materials such as a high friction coating or a silicone may be used.
The novel invention offers a new alternative type of foot care product/protective garment that alleviates the adverse effects, common pain, discomfort and skin irritations experienced when wearing high-heeled shoes. The invention offers a new type of optimized foot care product that simultaneously serves the function of, replaces the need for, and eliminates the drawbacks of both the traditionally known shoe insert and the traditionally known sheer or opaque pantyhose/stocking/tight hosiery garment. The novel form, structure, and method and process of making the invention provides both a full insole cushioning system and a protective hosiery membrane for the foot, a device that is substantially not visible when worn.
The present invention redefines the form and structure of the traditionally known cushioned shoe insert from an added material object that lies inert and lifeless on the inner shoe sole base into a full insole cushioning system for the foot that integrates into the look, feel and function of the morphology and biomechanical performance of the foot body, plantar surface, and plantar ST padding. Unlike the traditionally known shoe insert, the novel cushioning system according to the invention is worn on the foot body as a clear, breathable, continuous, three-dimensional, self-supported, biomorphic foot-shaped, seamless, non-woven, surface membrane with varied contoured shapes, thicknesses, material properties throughout, that directly conforms to the foot skin and plantar surface and works as a second skin or pseudo soft-tissue padding for the foot. The invention grips, flexes, and conforms with the foot and flows and deforms alongside the natural plantar ST padding without compressing or bottoming out to maintain total contact with the entire plantar surface and complete foot body during biomechanical foot changes such that it becomes part of the force bearing surface area of the foot at all positions and moments in time to offload externally applied vertical pressure forces and provide comfort to the foot. Unlike other known shoe inserts, the “dual friction interface” surfaces provide a low friction surface at the inside surface of the membrane in contact with skin and a higher friction surface at the exterior surface in contact with the shoe (including the sole) to minimize slippage of the foot and lessen shear and frictional forces while still permitting the foot to propel properly for walking.
The invention is the first-ever cushioned hosiery-like membrane for the foot during high-heeled wear that is of a highly conforming, biomorphic-shape with contoured thicknesses that integrates with the look, feel and function of the morphological form and biomechanical performance of the foot body, plantar surface, and plantar ST, such that it is substantially undetectable to the eye. The novel invention is the first-ever protective garment for the foot during high-heeled shoe wear that is largely visually undetectable and also permits the perform/function closest to its “bare state” as an enhanced version of itself.
The invention also redefines the look, feel, form and structure of the ubiquitous sports cushioned sock into a new type of high performance, clear, protective garment for the foot suitable for high-heeled shoe wear. The invention offers the performance features similar to that of the specialty cushioned insole athletic sock in a completely refashioned and superior, clear, light-weight, ultra-thin, non-woven, seamless, optimized, form that is suitable and geared towards use with the high-heeled shoe. The invention includes an entirely clear, substantially invisible, breathable, non-woven, water-absorbent, high performance cushioned sock for the foot. The present invention offers a new type of everyday hosiery-like membrane that has performance features not found in the traditionally known sports socks or sheer nude stocking or pantyhose typically worn with high-heeled shoes and other shoes such as flats or sneakers
The present invention also includes the method and process of making the device described herein.
The invention also includes another embodiment of the device comprising a single membrane comprising a) thin portions with a minimal thickness and b) thicker areas at and around the major points of contact on the bottom of the foot at the plantar soft tissue when wearing a high-heeled shoe, that is, the parts of the invention under the big toe, metatarsal heads of the forefoot, and the heel. The increased thicknesses throughout various parts of the structure of the device work to counteract the stresses experienced by the wearer of footwear. For this embodiment made of a single membrane material, the membrane is most preferably a single durometer silicone. The silicone membrane is conformable and contourable to the wearer's foot shape. The silicone membrane is a stretchable, thermoset rubber, that resists deformity and maintains the memory and shape of that to which it is pre-formed or molded, unlike a PU which is thermoplastic. Tearing of the silicone membrane is undesirable. Accordingly, the silicone membrane is preferably equal to or greater than about 0.25 mm thick when made from a shore A 3-10 durometer. More preferably, the silicone membrane has a thickness of at least about 0.5 mm around the entire device with thicker areas at the major points of contact, e.g., the big toe portion of the device, the front portion of the device under the metatarsal heads when the device is worn, and the heel portion of the device.
For this embodiment made of a single membrane material, the coefficient of friction on the inner surface of the device (the portion in contact with the user's foot) is greater than the coefficient of friction on the outer surface of the device (the portion in contact with the insole of the footwear). This is desirable because of the intended manner of use of the device—the device is intended to first adhere onto the user's foot and then the user places his/her foot with the device on it into the footwear. Accordingly, the lower/outer surface of the device must be capable of sliding, to a degree, inside the footwear when placing the footwear on. The frictional propertied of the outer surface are still high enough, though, to help grip the foot into the shoe and prevent slippage forward or up and out of the shoe at the back heel portion. The higher friction surface at the exterior surface is, therefore, desirable because it helps secure the foot within the shoe. Thus the device, according to the invention, has a different tackiness on the inner/upper surface than on the outer/lower surface. The lower/outer surface of the device slides easier than the inner/upper surface.
For this embodiment of the invention comprising one silicone membrane layer, an increased tackiness (higher coefficient of friction) on the inner/upper surface can be achieved when the silicone membrane is comprised of a single silicone material by molding the device such that the parts of the inner/upper surface or the entire inner/upper surface of the device has a very smooth surface finish. Alternatively, an adhesive can be applied to parts of, or the entire, inner/upper surface of the device. To reduce the tackiness and achieve a lower coefficient of friction on the outer/lower surface, the silicone material of the device can be molded/made such that outer/lower surface has a more texturized, as opposed to smooth, surface finish. Still further, alternative methods to reduce the tackiness (create a lower coefficient of friction) of the outer/lower surface with or without modifying the inner/upper surface include, for example, applying a low friction coating or talc powder that lessens the tack and gives the silicone lower frictional properties.
Accordingly, for this embodiment comprising a single silicone membrane material, the inner/upper surface of the device that will be placed in contact with the user's foot includes a higher tackiness than the outer/lower surface of the device intend to be placed in contact with the footwear.
A greater tackiness (greater frictional properties) on the inner/upper surface of the device, or parts of the inner/upper surface of the device, is particularly desirable for those embodiments of the invention intended to adhere to the underside of the user's foot, e.g., pad(s) for under the big toe, the forefoot, and/or the heel. Any of the aforementioned methods and structures can be used to create the desired increased tackiness on the inner/upper surface. Preferably, and within the scope of this invention, the device includes a second layer of silicone having a lower durometer than that of the silicone membrane, on the inner/upper surface of the device with a greater “tackiness.” This second layer ensures that the membrane has maximum self-adhering properties to the foot and allows a more sturdy, higher durometer silicone (with less ‘tack’) to be used to make the base silicone membrane that supports the second silicone layer. The second silicone layer can be on the entire inner/upper surface of the silicone membrane and/or portions of the inner/upper surface of the silicone membrane can have the second silicone layer. Such a two layer, dual durometer, device is expressly included in the scope of the invention. This version of the invention, like the single layer silicone membrane, has increased tackiness (higher coefficient of friction) on the inner surface and less tack and a lower coefficient of friction on the outer/lower surface. The second silicone layer preferably comprises a very low durometer, gel-like, silicone with a coefficient of friction of about 0.75 to 1.0 or higher (such as a shore 00 20 to 40 or any silicone material typically below the shore A scale and measured on the shore 00 scale)—which is higher than the coefficient of friction for the supporting/base silicone membrane layer which is preferably equal to or less than a coefficient of friction of about 0.75 (e.g., a Shore A 3 to Shore A 10). The tack factor also serves a purpose beyond just initially positioning the device correctly. It also ensures that the device stays in place and continues to makes complete and total contact with the foot skin surface at all times to better offload forces acting on the foot.
The invention is a foot-contouring device/membrane that closely resembles the curvilinear shape of the foot's plantar surface and readily conforms to the foot (that is, it has both an exterior and interior surface that closely resembles the foot contours). The device acts as a shield to protect and maintain the natural soft-tissue form and distribution that the foot has before weight bearing and loaded conditions occur. The device allows the foot's soft-tissue to maintain its force dissipation/shock absorption properties. The device provides supplemental thickness to areas of the foot's soft-tissue padding that are known to decrease in thickness during weight bearing activities. The device, therefore, also provides a cushioning effect for comfort and support of the foot. When the device is placed on the foot within a shoe, it has been shown to have an anti-slip and suction effect that makes it such that the user's foot is less likely to slip out of and move or wobble within the shoe due to the interface of the device between the foot skin and shoe.
The surfaces of the device are pre-formed/molded to have a shape in cross and longitudinal sections that help it to closely conform to the wearer's foot. For example, the device is pre-formed/molded to have a cupping elliptical surface in cross and longitudinal section at the toe area of the device to enable it to closely conform to the toe's bottom surface. The device has a pre-formed/molded cross section at the forefoot area of the device comprising an undulating curvilinear shape consisting of two convex elliptical shapes connected in the middle by a concave elliptical shape. The device has a pre-formed/molded shape at the heel portion of the device that consists of a ‘C’ cupping shape in both cross section and longitudinal section.
The device of the invention may also be multi-layered with more than two layers of silicone comprising a first silicone membrane that is self-supporting with additional layers of material (silicone or others) added.
The invention may be held in place by a shoe or be used and/or adhered to the user's foot outside of the footwear. For the embodiment of the invention with a tacky inner surface resulting from the properties of the silicone, the ‘self-adhering’/tacky inner surface allows the device to remain in position on the user's foot without the use of traditional adhesives and without having to be attached to or used with the support of a shoe. The device is ideally placed on the foot and then the foot and device is placed in the shoe. Or the device can be placed or adhered into the shoe and then the foot can be placed in the shoe with the device. The device can also, be manufactured as part of footwear.
Alternatively, the invention may become part of a hosiery item and laminated or adhered into a sock or tight. The device can be laminated on the inner and/or outer surface of the hosiery item. A kit can be provided for the user to do this or it can be manufactured into the hosiery item. In this version of the embodiment, the inner surface of the device is better held in place by the support of the hosiery item, so the aforementioned methods used to increase the tack if the inner surfaces are not as useful.
The overall thicknesses of the device are such that not an unnatural amount of bulk is added under the wearer's foot. Rather, additional thickness is added at certain areas to compensate for the soft-tissue thickness reduction that occurs due to compressive forces acting on the toe, forefoot and heel during weight bearing activities such as walking and standing. The silicone membrane embodiment is preferably less than about 3 mm at its thickest areas to prevent taking up too much room in the shoe and causing discomfort. The device, however, could be as thick as 4 mm at certain areas, such as the portion of the device in the front under the first metatarsal head (medial side of the device in the front area) to compensate for the compressed soft-tissue reduction that occurs at that region of the foot which is showed from research to typically be as high as a range of about 4 mm.
In the most preferred embodiments, the device has the greatest thickness at the central most areas of the device at the big toe, forefoot and heel regions—the areas of the foot know to have the most contact/impact with ground forces. The greatest thickness in the big toe region of the device is preferably between about 1.5 to 2 mm in the central portion thereof; the greatest thickness in the forefoot region of the device is preferably between about 1.5 to 3 mm; and the greatest thickness in heel area of the device is preferably between about 1 to 2 mm. The portions of the silicone membrane between the areas of the device that cover the areas with the most contact/impact are about 1 mm thick. The edges of the silicone membrane preferably taper or bevel to smaller thickness. Edges are preferably about 0.5 mm thick and can be as thin as 0.25 mm, although lower durometer silicone tears more easily at that thickness.
Even though the device is stretchable and conformable, the device is ideally sized to accommodate various ranges of foot sizes, lengths and widths.

DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description of an embodiment given below, serve to explain the principles of the present invention. Similar components of the devices are similarly numbered for simplicity.

FIG. 1 is a perspective view of one embodiment of a device according to the invention in a sock form showing a position as if the device is worn and in a high-heeled shoe.

FIG. 2 is another perspective view of one embodiment of a device according to the invention in a sock form showing the portions of the device.

FIG. 3 is a plan view of one embodiment of a foot membrane according to one embodiment of the invention in a sock form showing a foot (in dashed), the points of most impact thereon when the foot is in a high-heeled shoe, and one example of the contouring of the device according to the invention at the points of most impact.

FIG. 3A is a perspective view of device according to the invention in a sock form showing a position as if the device is worn and in a high-heeled shoe.

FIG. 4 is a cross section taken at line 4-4 in FIG. 3 showing the parts of the foot membrane device and example layering of membranes and gel-like material at areas of the device at the toe portion, the front portion and the heel portion.

FIG. 4A includes enlarged views of parts of the device shown in FIG. 4.

FIG. 4B is another embodiment of the invention in sock like form as shown in FIG. 4 with alternative layering patterns for the membranes and gel-like materials including a single gel-like material layer between two membranes (termed tpu film membrane on FIG. 4B) at the heel portion, two layers of gel-like material sandwiched between three layers of membrane at the front portion beneath where the metatarsals are when the device is worn, and a single gel-like layer of material between two layers of membrane at the toe portion beneath where the big toe is when worn.

FIG. 5 is a sectional front view of the foot and device taken in the front portion also including a table showing example thicknesses of the device along its width from the medial side to the lateral side for various example embodiments.

FIGS. 6A, 6B, 7A, 7B and 7C show example configurations of the device according to the invention by way of example at the front portion under where the metatarsal heads and the toe would be when worn, including a single layer of gel-like material between two layers of membrane, using two (or more) sandwiched layers of gel-like material between membranes put together, or a plurality of gel-like material layers together between two membrane layers.

FIG. 8 is yet another embodiment of the invention in the shape of a sock similar to the embodiment shown in FIG. 1 except the device has one or more openings at the toe portion of the device through which the toes pass through and a small piece at the toe portion under where the big toe is when the device is worn. In this embodiment, all of the toes are exposed outside the device, which is advantageous for an open toe shoe. The device includes a component at the toe portion under the big toe with one or more membrane layers and/or one or more gel-like material layers.

FIG. 9 is another embodiment of the invention similar to the embodiment shown in FIG. 8 without any component in the toe portion where the big toe would rest when worn.

FIG. 10 is another embodiment of the invention similar to the embodiment shown in FIG. 9 with apertures for each toe at the front portion of the device. This embodiment of the device is also configured to go higher at the back portion of the device so that the opening is higher on the leg when worn.

FIG. 12 is a plan view of another embodiment of a device according to the invention in stick-on form showing the device on a foot, the points of most impact thereon when the foot is in a high-heeled shoe, and one example of the contouring of the device according to the invention at the points of most impact.

FIG. 13 is a cross section taken at line 13-13 in FIG. 12 showing the parts of the device and example layering of membrane(s) and gel-like material layers.

FIG. 14 is a perspective view of the device shown in FIGS. 12 and 13 showing the device on a foot and the foot in a shoe.

FIGS. 15 and 16 shows further configurations for the device according to the invention, one with an open toe portion and the other with a closed toe portion. The configurations shown in FIGS. 15 and 16, as for other embodiments, could include adhesive on the entire interior of the device, on select parts of the interior such as, for example, at areas where the membrane makes contact with skin when worn, and/or at the points of major impact. These embodiments could also be made without any adhesive on the interior of the device. The configurations shown in FIGS. 15 and 16 could also be used as a shoe insert or shoe liner.

FIGS. 17 and 18, and 19 show yet further embodiments of the invention in the form of a shoe insert.

FIG. 20 is yet another embodiment of the invention in the form of (integrated into) a hosiery item such as, panty hose, or tights.

FIG. 21A is a perspective view of another embodiment of a device according to the invention showing the device on a foot in a high-heeled shoe. The device is shown with an open toe portion, an open forefoot portion, an open mid foot portion and an open heel portion. Such a configuration could include a second layer of silicone or an adhesive on the inner/upper surface. This open configuration could also be made in an embodiment with just a single layer of silicone membrane. FIG. 21B is a longitudinal cross sectional side view of the embodiment shown in FIG. 21A taken along the longitudinal axis of the device from the front of the big toe to the back of the device under the heel.

FIG. 22 is a perspective view of the embodiment of the device shown in FIGS. 21A and 21B without the shoe.

FIG. 23 is a plan view of the embodiment shown in FIGS. 21A, 21B and 22 showing a foot (in dashed) and contouring of the device according to the invention at the points of most impact (also shown in dashed lines).

FIG. 24 is a cross section taken at line 24-24 in FIG. 23 showing the parts of the device and an example embodiment with a single silicone membrane and a second silicone (gel-like) layer on top of the silicone membrane.

FIG. 25 shows cross sections of the device taken at lines 25A-25A, 25B-25B, and 25C-25C in FIG. 23.

FIG. 26 shows an alternative embodiment of the device shown incorporated into an article of footwear comprising a single silicone membrane and under fill material in the negative space between the underside of the membrane and the upper surface of the insole of the footwear.

FIG. 27 shows an alternative embodiment of the device shown incorporated into an article of hosiery comprising a single silicone membrane and a lamination adhesive layer to fasten the device to the underside of the hosiery in the foot area.

FIG. 28 is a longitudinal cross sectional side view of the embodiment shown in FIG. 21A taken along the longitudinal axis of the device similar to FIG. 21B. FIG. 28 shows the soft tissue of the user's foot and the points of impact under the toe portion, forefoot portion and the heel portions of the device.

FIG. 29 is a sectional front view of the foot and device shown in FIGS. 21-28 taken in the forefoot portion (the location of section line 25B-25B in FIG. 23) also including a table showing example thicknesses of the device along its width from the medial side to the lateral side for various example embodiments.

FIG. 30 is a sectional front view of the foot at the forefoot area similar to FIG. 29 under an unloaded and loaded condition. The Figure also shows a sectional front view of the foot with the device according to the invention as shown in FIGS. 21-29 taken in the forefoot portion in a loaded condition. The Figure depicts the beneficial effects of the device on the foot, specifically the padding beneath the metatarsal heads of the user, which lessens the amount of soft tissue reduction thus providing better padding.

DETAILED DESCRIPTION

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description of an embodiment given below, serve to explain the principles of the present invention. Similar components of the devices are similarly numbered for simplicity.
The device of the present invention comprises a unitary structure that is worn on the foot and/or adheres to the foot. The device includes a) a heel portion adapted to engage at least the plantar portion of the heel of a user's foot, preferably also at least some of the sides and the back (posterior) of the heel, b) a back portion adapted to engage the back of the foot behind the arch of the foot including the heel and ankle, c) a middle portion adapted to engage at least the arch of the foot and in at least some embodiments also including the sides and top of the middle portion of the foot, d) a front portion adapted to engage at least the ball aspect of the foot at the metatarsal heads (the forefoot) and in some embodiments the side and top of the foot around the metatarsals, and e) a toe portion adapted to engage at least one of the toes of the foot, namely the big toe, and in some embodiments all of the toes.
In the embodiment shown in FIG. 1, the device is configured in the shape of a tubular sock having a front 110, a back 120, a top 130, a bottom 140, an inside/interior having an inside surface 155, an outside/exterior 160 having an outer surface 165, and an opening in the top and back of the device 170 forming the entrance to an aperture 150 inside the device. As shown in FIG. 2, the device includes a back portion 220 adapted to engage the back of the foot behind the arch including the heel and ankle which includes a heel portion 210 adapted to engage at least the plantar portion of the heel of the foot, preferably also at least some of the sides (lateral and medial) and the back (posterior) of the heel, a middle portion 230 adapted to engage at least the arch of the foot, a front portion 240 adapted to engage at least the ball aspect of the foot at the metatarsal heads (the forefoot) and preferably sides of the forefoot, and a toe portion 250 adapted to engage at least one of the toes of the foot, namely the big toe and preferably the sides of the big toe.
According to one embodiment, the device is comprised of at least one membrane around the entire device and at least one layer of gel-like material attached/connected to the at least one membrane at each of the heel portion 210, the front portion 240 at the part adapted to engage the bottom of the forefoot, and the toe portion 250 at the part adapted to engage the underside of the big toe, to create cushioned areas under parts of the foot when the device is worn.
The membrane is preferably made of a monolithic structured barrier film that is breathable and allows vapor to pass through by diffusion. The membrane is stretchable and returns to its original shape when released (e.g., taken off after wear). The membrane material prevents water and contaminants from passing through it. For example, the membrane can be made from thin polyurethane film, also known as a TPU (thermoplastic polyurethane). TPU films come in clear finishes that are either transparent or translucent, with a slightly milky whiteness, with either gloss or matte finishes. Depending on the shape of the specific embodiment of the invention, this material can be utilized in a process of making where the already made and extruded thin sheets are purchased and are thermoformed or heat stretched into a 3D shaped film membrane to make up some or all of the membrane layers of the invention.
Preferably, the gel-like material comprises a polymer-based, viscoelastic, gelatinous material. The gel-like material is soft, yet substantially non-compressible, and conformable (capable of molding around) to the surrounding areas of the plantar surface of the foot when the device is worn without reducing in thickness to the point that all of its cushioning ability is lost (bottoming out). The gel-like material according to the invention may be a moist and/or self-adhering (e.g., sticky) polymer, such as a hydrogel, or a naturally sticky silicone for providing a soothing feeling to the skin when in contact. The gel-like material can be hydrophilic or have a hydrophilic coating so it can absorb water and perspiration during wear.
The gel-like material could be a polymer-based gel, such as a viscoelastic polyurethane gel, or a silicone. The gel-like material can be on top of (attached to) the membrane material and/or sandwiched between layers of membrane layers. The gel-like layer acts like a cushion helping to absorb forces and reduce stress and strain on the foot. For example, the gel-like material conforms to the protruding shapes of the metatarsal heads of the foot when weight is placed on the forefoot/ball-of-foot while wearing the device. When the gel-like layer is positioned such that it is in direct contact with skin, a softer, more conformable, gel-like material is used as compared to when the gel-like material is a layer of material not in direct contact with the skin in which case a harder and more durable gel-like material can be used.
The gel-like material could gradate from softer and more conformable at the inner layers of the device closest to the upper surface/inside 150 where the device contacts the foot skin and harder at the outer layers closest to the exterior/lower surface/outside 160 where the device contacts the upper surface of the insole of a shoe. If only one gel-like layer is used in the device, then the gradation could occur within the one gel-like layer as opposed to between separate gel-like layers. The gradation makes the padding effect of the device more like that found in the natural plantar ST and ensures that the foot skin can sink into a soft and more conformable gel-like layer in contact with or closest to the surface of the foot skin.
The invention also includes more than one gradation change in a single gel-like layer. For example, a single gel-like layer could include five gradation changes, most hard at the outermost layer closest to the outside 160, 80% of the hardness of the outermost material at a next portion closer to the inside 150, 70% of the hardness of the outmost material next, then 60% and 50% for the successive materials in the gel-like layer. Alternatively, there could be three gradations—hard/medium/soft, or two gradation changes—hard/soft. The same gradation effect can be achieved using multiple gel-like layers each having a different hardness. For example, the device could have three gradations with five gel-like layers at the bottom 140 of the front portion 240, the outermost two layers could be the hardest, the next two gel-like layers could be of medium hardness, and last gel-like layer closest to the inside 150 could be of the soft gel gradation. For two gradation changes throughout six gel-like layers at the bottom 140 of the front portion 240, three layers could have the harder grade gel and three layers could have the softer grade gel.
In one embodiment, the device comprises at least one gel-like material layer at the bottom (underside) areas 140 of the toe portion 250 under where the device is adapted to engage the big toe, the front portion 240 under where the device is adapted to engage metatarsal heads, and the heel portion under where the device is adapted to engage the heel. A plurality of gel-like material layers could be used in embodiments of the invention to more closely configure the device to resemble the natural plantar ST structure and ensure that each individual gel-like material layer grips the foot due to the layered support of the at least one membrane layers which works in tension on the foot when the device is used/worn. In some embodiments, the number of layers of membrane and gel-like material, and/or the total thickness, is greater at the front portion 240 and the toe portion 250 than at the heel portion 210 because those areas experience more pressure during high-heel shoe wear. The number of layers of membrane and gel-like material at the heel portion 210, the front portion 240 and the toe portion 250 can vary between embodiments.
Preferably, each the heel portion 210, the front portion 240 and the toe portion 250 of the device have at least one layer of gel-like material. Alternatively, the heel portion 210 has at least two, the front portion 240 has between two and six, and the toe portion 250 has between two and four. The layers of membrane and gel-like material according to the invention function as a structure similar to the geometry of the plantar ST. Accordingly, more layers allow the device to function like real plantar ST and grips the foot.
The thicknesses of the gel-like material layers used in the device can vary as needed throughout the device to achieve the desired device configurations. For example, if two gel-like layers are used at the forefoot and the range of thickness in the inner regions of the inter-membrane gel layers are 2 to 4 mm, the thicknesses of each of the two gel layers would be 1 mm, at the area that totals a 2 mm thickness and each 2 mm at the areas that total 4 mm.
In one embodiment, at the front portion 240 of the device, the thickness for the bottom 140 is created by layering the membrane and the gel-like material to match the generally known thickness changes of the plantar ST across the width of a foot from the medial side to the lateral side when in a natural and flat position. When worn and when in a loaded state in a high-heeled shoe, the device thereby provides padding or cushioning to the foot as if it were still unloaded.
In an unloaded state, when the foot is in a prone position, there is a gradation in thickness of the plantar ST across the width of the foot. The plantar ST is thicker underneath metatarsal head 1 (M1) and thinner under metatarsal head 5 (M5). Studies have shown that the decrease in plantar ST thickness under the metatarsal heads from M1 to M5 is about 3.6 mm, give or take a standard deviation, across the foot with about 13.65+/−1.95 mm under M1 and about 10.07+/−1.19 mm under M5. The plantar ST thickness underneath the metatarsal heads (M1, M2, M3, M4 and M5) are generally know to be as follows: MT1: 13.65 mm, MT2: 12.27 mm, MT3: 11.40 mm, MT4: 10.77 mm, and MT5: 10.07 mm.
Typically, the greatest decrease in ST thickness is between M1 and M2 (about 1.5 mm) with a lesser decrease of thickness from M2 to M3 (about 0.9 mm) and then a lesser decrease from M3 to M4 (about 0.6 mm) and another decrease of thickness between M4 to M5 (about 0.7 mm). The foot device according to the present invention is configured to mimic the aforementioned thickness of the plantar ST under the metatarsal heads using one or more layers of membrane and one or more layers of gel-like material (with our without tapering) at the bottom (underside) 140 of the front portion 240 beneath the areas where the device is adapted to contact the points of main contact on the metatarsal heads. Preferably, the layering according to the invention, like the plantar ST of a healthy foot in an unloaded state, subtly decreases in thickness from M1 to M5.
The thickness of the plantar ST under the metatarsal heads changes when a foot is placed in a loaded state, particularly when in a high-heeled shoe. The plantar ST under the metatarsal heads compress non-uniformly across the width of a foot. The device of the present invention therefore includes alternative configurations for the thickness of the device, other than the aforementioned configuration with a decrease from the medial side as viewed on the foot to the lateral side, such as a configuration adapted to reflect about the same amount of the plantar ST reductions at the forefoot when maximum compressibility has been reached in a high-heeled shoe. The plantar ST reductions under maximum compression in a high-heeled shoe of 4 cm heel (1.57 inch) are MT1: 3.66 mm, MT2: 4.64 mm, MT3: 4.21 mm, MT4: 3.66 mm, and MT5: 3.26 mm. The plantar ST reduction increases from MT1 to MT2 where it is the greatest and then subtly decreases from MT2 to MT5. Between MT2 and MT5 there is a 1.38 mm ST reduction. MT1 has about 1 mm less of a plantar ST reduction than MT2. The device according to the invention is configured at the bottom 140 of the front portion 240, the part adapted to engage the foot under the metatarsals, to replace/restore the padding lost as a result of the plantar ST reductions. Accordingly, one embodiment of the invention has less thickness near the medial side of the device at the bottom 140 of the front portion 240 where the device would engage MT1 when worn than under the part of the device that would engages MT2 (the part at about the center of the width of the device, slightly closer to the medial side) which would have the greatest thickness and then tapers down in thickness therefrom towards the lateral side of the device at the bottom 140 of the front portion 240 under where the device would engage MT5 when worn.
The desired thicknesses for the device under the heel portion 210, the front portion 240, and the toe portion 250 result from a combination of the layering of membrane and gel-like material layers. The one or more gel-like layers forming the device preferably contour and taper from a nominal thickness at the bordered edges to a greater thickness at the innermost region(s). The tapering of the gel-like layers at the bordered edges to a nominally thin amount functions to help the gel-like layers transition smoothly to the at least one membrane layer.
When only one gel-like material layer is used at either the heel portion 210, the front portion 240, and the toe portion 250, then the contouring/change in thicknesses throughout the inner region(s) occurs within that one gel-like material layer. For embodiments using more than one gel-like material layer at the heel portion 210, the front portion 240, and/or the toe portion 250, the change in thickness of the innermost regions of the gel-like material layers results from contouring of the individual gel-like material layers and the layering and building up the multiple gel-like material layers. This is achieved, for example, by successively decreasing the outer/bordered area of the gel-like material layers inwards to create contoured thickness changes. For example, if three gel-like material layers are used at the front portion, the first gel-like material layer may cover the area adapted to engage under MT1 (near the medial side of the device) to MT5 (near the lateral side), while the next gel-like material layer may only cover the areas under MT1 to MT4 (more medial than M5 about halfway between the center of the device and the lateral side of the device), and the next gel-like material layer may only cover the area under MT1 to MT3 (at about the center of the width of the device) and so on. In addition to this layering method, each of the three layers of gel-like material layer could also slightly change in thickness from thinner at the area under the lateral side of the front portion 240 to thicker near the medial side of the front portion 240. This configuration, together with the successive change of shape in the bordered area of each gel-like material layer, creates a contouring and thickness variation under the metatarsals of the foot when the device is worn where the part under MT5 has the least amount of gel-like material layer thickness, MT4 has slightly more thickness than MT5, MT3 has slightly more thickness than MT4, MT2 has slightly more thickness than MT3, and MT1 has slightly more thickness than MT2.
The device according to the invention has preferred thicknesses at different parts of the device. The maximum thickness at the heel portion 210 is preferably between about 1 mm and 2 mm. Preferably, the gel-like material layer at the heel portion 210 will have less thickness, variation and contouring (less taper) than at the front portion 240 and the toe portion 250. The maximum thickness of the device at the toe portion 250 adapted to engage the big toe is between about 1.5 and 2.5 mm, preferably greater than the maximum thickness of the device at the heel portion 210 because more pressure is put on the big toe during high-heeled shoe wear. The maximum thickness at the front portion 240 is between about 1.5 and 4.5 mm depending on the specific embodiment as shown in the table in FIG. 5.
Referring to the figures, one embodiment of the invention is shown in FIGS. 1-4A. FIG. 2 is a view showing an embodiment in a sock form showing the portions of the device. FIG. 3 is a plan view of one embodiment of the device showing a foot (in dashed), the points of most impact on the foot and the device when worn in a high-heeled shoe, and one example of the contouring of the device according to the invention at the points of most impact designated by the solid circles. As shown in FIG. 3, the points of most/greatest impact on the foot and the soft tissue of the foot when a high-heeled shoe is worn are located under the hallux at H1, under each of the metatarsal heads of the foot designated M1, M2, M3, M4 and M5, and under the heel at the point designated C1, it being understood that the points of impact shown on FIG. 3 are approximations and that the actual exact locations may vary slightly on each person depending upon many factors, including physical traits, walking motions, size of the shoe, the walking surface, etc. Preferably, the invention is configured such that the thickness of the device contours from a nominal thickness up to a greatest thickness under these points of most impact (H1, M1, M2, M3, M4, M5 and C1. The thicknesses at all of the points of most impact do not all need to be the same as each other.
FIG. 3A shows the foot membrane device 4 worn on a foot and in a high-heeled shoe 6. The outer border of the device 2 is where it ends and the natural skin 1 of the user is uncovered and exposed outside the device 4. The pants/clothing 3 of the user is shown as covering the outer border 2 of the device 4. The parts of the device 4 under the points of most impact, under the heel, the metatarsal heads, and the hallux are cushioned/thickened areas 5 of the device 4, preferably made from a membrane/gel composite.
The contouring shown in FIG. 3 may, but need not, be the same as the layering of the membrane layers and gel-like material layer(s) in the device. The contouring shown in FIG. 3 may be accomplished with one or a plurality of layers of membrane with a combination of one or more layers of gel-like material.
For example, FIG. 4 is a longitudinal cross section taken at line 4-4 in FIG. 3 showing the parts of the foot membrane device and example layering of membrane and gel-like material. The various parts of the device shown in FIG. 4 are identified as follows:

- TBLa: Thickness of TPU base layer at the ankle/end of membrane surface: to be 1-3 mil, preferably 1 mil to be as thin as possible so not detected as a termination line on the skin. 6-20 mil would be maximum thickness for more durable version.
- TBLc: Thickness of TPU base layer at the heel region: to be 1-3 mil. Around 3 mil acceptable to make more durable as does not need to be as thin as TBLa and 6-20 mil would be maximum thickness. May have high friction coating on outer surface.
- TSLa: Thickness of secondary TPU layer/s: to be 1-3 mill, thinnest yet durable construction favored
- TBLf/h: Thickness of TPU base layer at the forefoot and hallux/big toe. Around 1-3 mil acceptable to make more durable as does not need to be as thin as TBLa and 6-20 mil would be maximum thickness. May have high friction coating on outer surface. See details
- TBLt: Thickness of TPU base layer at the top foot region: to be 1-3 mil, around 3 mil acceptable to make more durable as does not need to be as thin as TBLa and 6-20 mil would be maximum thickness
- TC1:Thickness of gel at heel layer: to be 1 mm-2 mm max for high-heeled version and 2.5-3 mm (maybe 4 mm max) for more athletic version
- TM1:Thickness of gel at first metatarsal head. See table on FIG. 5 for values at other metatarsal heads
- TH1:Thickness gel at Hallux/big toe: will be 1.5 to 2.0 mm
- H1: impact force line at big toe
- M1: impact force line at metatarsal head
- C1: impact force line at heel

As shown in FIGS. 4 and 4A, the membrane layer 301, preferably termed the “TPU base layer,” is a layer of membrane 301 around the entire device. Some parts of the device include one layer of the membrane 301 and in other locations there are two layers of membrane 301 with a layer of gel-like material between them. For example, as shown in greater detail in the Details in FIG. 4A, the membrane is two layers, 302 (a primary membrane layer) and 303 (a secondary membrane layer) at parts of the device. Between the primary and secondary membrane layers is/are one or more layers of gel-like material 304. The gel-like material 304 can be a uniform gel-like material or it can be configured to include two or more gradients of gel-like materials having different properties, such as, for example, one having softer properties at the innermost position (designated G1) and one having harder properties at the outermost position (designated G2) as shown in the Details. The outer surface 165 of the device is preferably a high friction surface 305 and the inner surface 155 is preferably a lower friction surface 306.
The thickness of the device at the bottom (underside) 140 of the front portion 240 around the points of most impact (at the parts adapted to engage M1, M2, M3, M4, and M5 when worn, that is, TM1, TM2, TM3, TM4, and TM5) can be a uniform thickness. Alternatively, as shown in FIG. 5, and more preferably, the thickness from TM1 to TM5 is not uniform across the width of the device but rather varies along the width at the points of most impact in one or more configurations as set forth in the table. Accordingly, the maximum thickness of the device at the bottom 140 of the front portion 240 may be as much as about 4.5 mm at the portion adapted to engage the foot under the second metatarsal head (M2). Smaller thicknesses are used at the other areas of the front portion 240 beneath the other metatarsal heads (M1, M3, M4 and M5) when worn, such as down to 3.3 mm under M5 as shown in FIG. 5 for embodiments that contour to resemble the plantar ST reduction with a 4 cm high-heel shoe. In another embodiment configured to resemble the soft tissue changes to a bare foot on a flat surface, as also shown in FIG. 5, the maximum thickness of the device at the bottom 140 of the front portion 240 (under the metatarsal heads when worn) may be as much as about 4.0 mm at the fifth metatarsal head (M5) (the lateral side of the device) with smaller thicknesses at the other metatarsal heads (M1, M2, M3 and M4) down to about as low as 1.7 under M1 (on the medial side of the device) in one embodiment. It is understood that all of the configurations for the thickness across the width of the front portion 240 of the device from the medial to the lateral side (under the metatarsal heads of the foot when worn) included in the table shown in FIG. 5 are within the scope of the invention. In addition, the invention also includes the various layering configurations possible using the membrane and the gel-like material to create those thicknesses. For example, as shown in FIG. 6, the desired thicknesses at the bottom 140 of the front portion 240 (under the metatarsal heads when worn) as well as at other portions of the device (the heel portion and the toe portion) are created using a single layer of gel-like material between two layers of membrane, using two (or more) sandwiched layers of gel-like material between membranes put together, or a plurality of gel-like material layers together between two membrane layers. Other configurations including one layer of membrane and one layer of gel-like material, and other variations thereof including one or more layers of membrane and/or one or more layers of gel-like material are within the scope of the invention.
For example, the embodiment shown in FIG. 4B includes a single gel-like material layer 404 between two membranes (a primary membrane 402 and a secondary membrane 403) at the heel portion 210, two layers of gel-like material 404 sandwiched between three layers of membrane (402, 403 and 403) at the front portion 240, and a single gel-like layer 404 of material between two layers of membrane 402 and 403) at the toe portion 250. Accordingly, as shown by way of example in FIG. 4B, the number of layers of either the membrane or the gel-like materials around a single device can vary. In the embodiment shown in FIG. 4B, the secondary membrane layers 403 are laminated onto the outer surface of the primary membrane layer 402 to create 401 whereas the prior embodiment shown in FIG. 4A showed the gel layer(s) with the opposite structuring, that is, the secondary membrane layer(s) 303 and gel-like material 304 were placed and laminated and/or welded onto the inner membrane layer 302 to create 301. Either structure may be used for the invention. The thicknesses set forth in FIG. 5 are applicable for this embodiment as well.
FIGS. 6A, 6B and 7A, 7B, 7C show example configurations of the device according to the invention by way of example at the toe portion and the front portion under where the metatarsal heads would be when worn, including a single layer of gel-like material between two layers of membrane, using two (or more) sandwiched layers of gel-like material between membranes put together, or a plurality of gel-like material layers together between two membrane layers. The example embodiments shown in FIGS. 6A, 6B, 7A, 7B, and 7C include alternative constructions for the membrane and gel-like layer combination(s) under the points of most impact. In the embodiments shown, the gel-like layer is the thickest at the points of most impact under the metatarsal heads and then tapers to a nominal thickness. The membrane layer and gel-like layer construction can be (1) a singular layer of gel sandwiched between two layers of membrane as shown in FIG. 6B, or (2) one layer of gel-like material comprised of two different gradients of gel (G1 and G2) as shown in FIG. 7A, or (3) three layers of membrane with two separate gel-like layers in between the three layers, one having a particular set of characteristics and a uniform gradient G1 and a second gel-like layer with different characteristics having a uniform gradient G2 as shown in FIG. 7B, or (4) one layer of gel-like layer with two gradients of gel-like material on top of one membrane layer which makes direct contact with skin such that the gel-like material includes a surface that sticks to skin as shown in FIG. 7C.
As used in FIGS. 7A, 7B and 7C, the abbreviations mean the following

- G1: layer of gel-like material that is softest and closest to the soft/fatty tissue of the user, preferably viscoelastic in nature at the plantar region
- G2: layer of gel-like material that is harder and more durable than G1
- B1: the primary/base layer of membrane upon which any additional membrane/gel-like layers are placed either at outer or inner surface of the BL. The BL combined with other membrane layers through welding/lamination makes up a primary membrane structure that supports the gel-like layer(s)
- SLa: a secondary smaller layer of membrane material that is layered on the BL and covers a portion of or all of the gel-like layer area with an extension bordered, offset area that extends past the bordered area of the layer of gel-like material that it covers so as to be welded/laminated onto the BL and/or any other membrane layers (such as the SLB layer) to create a sandwiched, multi-layered membrane/gel-like composition depending on if the gel-like layer is added to the inner or outer base layer membrane surface, this can be placed on the inner or outer surface of the BL
- SLb: membrane layer between BL and SLa if two separate gel-like layers are used. The SLb is preferably welded onto the base membrane layer in the same way described with SLa. It is an in between membrane layer in a multi layered construction and like SLa it can be layered onto the outer or inner surface of the BL

In FIG. 7A, the SLa and BL merge into each other through welding/lamination to create a pocket to hold the gel-like material. In FIG. 7B, the SLa and SLb both layer onto the BL and merge with it through lamination/welding such that it creates a base membrane layer with two pockets in it for the gel-like material. In FIG. 7C, the SLa only covers a portion of the gel-like material so the rest can directly contact the foot skin, SLa
FIG. 8 is yet another embodiment of the invention in the general shape of a sock similar to the embodiments shown in FIGS. 1-7 except the device has openings 175 at the front of the front portion 240 where the toe portion 250 begins. The openings 175 function to let the toes of the wearer pass through the device. In this embodiment, when worn, the all of the toes are exposed outside the device, which is advantageous for an open toe shoe. The device further includes a component under the big toe (medial side of the bottom of the device) 510 when worn at the toe portion 250 with one or more membrane layers and/or one or more gel-like material layers. As for prior embodiments, there are layers of membrane and gel-like material at the heel portion 210, the front portion 240, and the toe portion 250 to create the desired maximum thicknesses set forth in the table in FIG. 5 with tapering.
FIG. 9 is another embodiment of the invention in the shape of a sock similar to the embodiment shown in FIG. 8 without any toe portion 250 components. Here again, as for prior embodiments, there are layers of membrane and gel-like material at the heel portion 210, the front portion 240, and the toe portion 250 to create the desired maximum thicknesses set forth in the table in FIG. 5 with tapering. The device has two openings 175 at the front portion 240 of the device through which the toes pass it being understood that there could be an opening 175 for each toe or less than five openings in which case at least two toes pass through an opening 175.
FIG. 10 is yet another embodiment of the invention in the shape of a sock similar to the embodiment shown in FIG. 9 with multiple openings 175 in the front portion 240 of the device and shown with a larger/higher back portion 220 which covers more of the ankle and leg when worn than the embodiment shown in FIG. 9. Here again, as for prior embodiments, there are layers of membrane and gel-like material at the heel portion 210 and the front portion 240, but not at the toe portion to create the desired maximum thicknesses set forth in the table in FIG. 5 with tapering. In the embodiment shown in FIG. 10, there are apertures 175 for each toe at the front portion 250 of the device. This embodiment of the device is also configured to go higher at the back portion 220 of the device so that the opening 170 is higher on the leg when worn.
Another embodiment of the invention, a version that adheres to (stick on) the underside of the foot, intended for open shoes, and shoes that expose the majority of the foot body, such as a strappy, high-heeled sandal, or a shoe that partially exposes the foot body, such as a high-heeled pump, and in particular is worn with clothing that exposes the majority of the leg, such as a skirt, is shown in FIGS. 12-14. The adhesive is a skin-friendly bio-adhesive coating/gel coating that does not leave a stick residue on the skin and can be repositioned easily. For example, BIOFLEX RX1400P has a TPU film with a single coated silicone gel adhesive. Also the adhesive would preferably be thin enough or distributed in a way as to not significantly alter the breathability quality of the membrane and/or gel layers. The adhesive may not be spread on the whole surface of the device, but in a hatched herringbone pattern, to leave portions of base membrane uncoated, to maximize the inherent breathability quality that the membrane offers. Alternatively, the same configuration for the device as shown in FIGS. 12-14 may exclude the adhesive and be used as a shoe liner or shoe insert or attached to a hosiery item. As for prior embodiments, there are layers of membrane and gel-like material at the heel portion 210, the front portion 240, and the toe portion 250 to create the desired maximum thicknesses set forth in the table in FIG. 5 with tapering.
Similar to FIG. 3, as shown in FIG. 12 the points of most/greatest impact on the foot and the soft tissue of the foot when a high-heeled shoe is worn are located under the hallux at H1, under each of the metatarsal heads of the foot designated M1, M2, M3, M4 and M5, and under the heel at the point designated C1, it being understood that the points of impact shown are approximations and that the actual exact locations may vary slightly on each person depending upon many factors, including physical traits, walking motions, size of the shoe, the walking surface, etc. Preferably, the invention is configured such that the thickness of the device contours from a nominal thickness up to a greatest thickness under these points of most impact (H1, M1, M2, M3, M4, M5 and C1). The thickness at all of the points of most impact does not all need to be the same as each other.
FIG. 13 shows a cross section taken at line 13-13 in FIG. 12 showing the parts of the foot membrane device and example layering of membrane and gel-like material. The various parts of the device shown in FIG. 13 are identified as follows:

- TBLa: Thickness of TPU base layer at the ankle/end of membrane surface: to be 1-3 mil, preferably 1 mil to be as thin as possible so not detected as a termination line on the skin. 6-20 mil would be maximum thickness for more durable, athletic version.
- TBLc: Thickness of TPU base layer at the heel region: to be 1-3 mil. Around 3 mil acceptable to make more durable as does not need to be as thin as TBLa and 6-20 mil would be maximum thickness. May have high friction coating on outer surface.
- TSLa: Thickness of secondary TPU layer/s: to be 1-3 mill, thinnest yet durable construction favored.
- TBLf/h: Thickness of TPU base layer at the forefoot and hallux/big toe. Around 1-3 mil acceptable to make more durable as does not need to be as thin as TBLa and 6-20 mil would be maximum thickness. May have high friction coating on outer surface. See details.
- TBLt: Thickness of TPU base layer at the top foot region: to be 1-3 mil, around 3 mil acceptable to make more durable as does not need to be as thin as TBLa and 6-20 mil would be maximum thickness
- TC1:Thickness of gel at heel layer: to be 1 mm-2 mm max for high-heeled version and 2.5-3 mm (maybe 4 mm max) for more athletic/durable version
- TM1:Thickness of gel at first metatarsal head. See table on FIG. 5 for values at other metatarsal heads
- TH1:Thickness gel at Hallux/big toe: will be 1.5 to 2.5 mm
- H1: impact force line at big toe
- M1: impact force line at metatarsal head
- C1: impact force line at heel

FIG. 14 shows the foot membrane device 604 worn on a foot and in a high-heeled shoe 606. The outer border of the device 602 is where it ends and the natural skin 601 of the user is uncovered and exposed outside the device. The parts of the device under the points of most impact, under the heel, the metatarsal heads, and the hallux are cushioned/thickened areas 605 of the device, preferably made from a membrane/gel composite. The sticky areas of the device in contact with the user's foot skin may cover all of the interior surface 155 of the base layer membrane or just portions of it. For example, the portions with adhesive or with a sticky surface may be at the outermost dashed line bordered areas seen at the heel portion 210, the front portion 240 and/or under the toe portion 250, possibly with an added interior strip at the middle underside portion that goes under the medial arch of the foot when the device is worn (not shown in dashed line). A natural bio adhesive (such as a silicon sticky coating) can be used for the sticky layer at all of the interior base layer surface or with the bio adhesive at film areas and the gel may just stick due to a natural stickiness of the silicon or type of gel-like material used.
FIGS. 15 and 16 show further configurations for the device according to the invention using the same numbering as in FIG. 14. The configurations shown in FIGS. 15 and 16 could include adhesive on the entire interior surface 155 of the device, on select parts of the interior 155 such as, for example, at areas where the device makes contact with skin on the foot (e.g., parts of the heel portion 210, the front portion 240, the middle portion 230, and/or the toe portion 250), and/or at the points of major impact. These embodiments could also be made without any adhesive on the interior 155 of the device. The configurations shown in FIGS. 15 and 16 could also be used as a shoe insert or shoe liner. As for prior embodiments, there are layers of membrane and gel-like material at the heel portion 210, the front portion 240, and the toe portion 250 to create the desired maximum thicknesses set forth in the table in FIG. 5 with tapering. In the embodiment shown in FIG. 16, portions or all of the interior 155 may include a sticky surface as described above (a natural bio adhesive can be used for the sticky layer at all of the interior 155 or with the bio adhesive film at areas and the gel-like material may just stick due to natural properties of a silicone or similar type gel used). Alternatively, this version may not be sticky at all and essentially just be like a ‘ped’ foot liner shape. FIGS. 17 and 18, and 19 show yet further embodiments of the invention configured in the form of a shoe insert. The numbering used in FIG. 14 is used in FIGS. 17-19 as well. The points where the device contacts the shoe can be points of attachment between the device and the shoe. The device could be attached using adhesive or other fastening means such as tape, stitching, etc. The voids created between the device and the shoe when installed in a shoe can be left empty or filler material(s) such as foam or gel-like material 609 can be placed therein. As for prior embodiments, there are layers of membrane and gel-like material at the heel portion 210, the front portion 240, and the toe portion 250 to create the desired maximum thicknesses set forth in the table in FIG. 5 with tapering.
In FIG. 19, the device becomes part of the shoe and is attached to it in methods similar to the way conventional insoles are attached, or the device is placed or stuck on, or it is made into the shoe in the shoe manufacturing process. This embodiment could also include parts with adhesive or adhering type properties on the inner surface 155 such as a bio-adhesive coating and/or natural stickiness of the gel-like material. Alternatively, the device's inner surface 155 may not have any adhering properties.
Preferably, the device includes a high-friction outer coating on the exterior 160 at the areas of the toe portion 250 (beneath where the big toe will be when worn) and/or the front portion 240 and/or the heel portion 210 that contacts the shoe sole to ensure that the foot does not slide forward in the inner shoe sole body and to contrast the lower friction inner surface 155 of the device. The high-friction outer coating could be spray applied or dip molded on as a finishing treatment or incorporated into the manufacturing process for the device if electrospinning or dip molding is used. The lower-friction inner surface of the device may be a material property of the membrane material (e.g., polyether TPU has a soft, smooth feel and is a low friction surface), or may be from special lubricants/additives embedded into the membrane material or laminated onto it. Alternatively, the inner surface 155 of the foot membrane device could be sprayed with lubricants or a low friction coating (such as PTFE) as a post-finishing treatment. Alternatively, the achievement of a low-friction inner surface may be enhanced or provided by a separate lotion or lubricant that is sold with the product and is designed to be put on the skin before the device is worn.
The low-friction inner surface of the device may also be achieved by using a gel-like layer/coating at the interior surface 155 of the heel portion 210, the front portion 240, and/or the toe portion 250 where the device makes direct contact will the skin of the foot. The inner surface 155 of the device, then, may have two different surface treatments; one of the gel-like material at the inner surface 155 of the heel portion 210, the front portion 240, and/or the toe portion 250, and the spray coating or additives/lubricant at the other parts of the inner surface 155 of the device.
For the embodiment of the invention that does not extend up the upper foot and ankle to be a sock shape but sticks to the bottom of the foot/plantar surface, a sticky, possibly removable, skin-friendly adhesive would be spray coated onto all or part of the inner surface of the device. If gel layers are placed at the inner surface 155 of the device at the innermost membrane layer, the gel of a moist/sticky polymer may be used that will have a natural stickiness, or a sticky coating may be applied to it. Even if a sticky coating and/or sticky gel is used the inner surface would still be designed to be of a lower friction than the outer surface.
FIG. 20 is yet another embodiment of the invention integrated into a hosiery item such as panty hose, or tights. Again, the numbering used in FIG. 14 is used in FIG. 20 to identify components. The hosiery item 608 includes within it the foot membrane device 604 worn on a foot. The outer border of the foot membrane device 602 is where it ends and the hosiery 608 continues without any additional components of the membrane layer. The parts of the device under the points of most impact, under the heel, the metatarsal heads, and the hallux are cushioned/thickened areas 605 of the device, preferably made from a membrane/gel composite. In this embodiment, the high friction surface that is typically on the outer surface of the foot membrane that makes contact with the shoe sole base, would, alternatively, be laminated or coated onto the outer surface of the hosiery device. This would further integrate the invention into the hosiery item.
The invention also includes embodiments where the membrane layer itself is made of gel-like material. For example, FIGS. 21 through 29 show embodiments of the invention comprising 1) a membrane made of gel-like and a second gel-like layer on the membrane layer, both layers made of silicone, and 2) a single layer of membrane made of gel-like material (e.g., silicone) without any second layer. In FIGS. 21 through 25 and 27-29, the silicone membrane functions as the base membrane and there is a second silicone layer (gel-like layer) along the entire inner/upper surface of the silicon membrane. In FIGS. 21A and 21B, the foot membrane device is shown in a high-heeled shoe 706. The outer border (outer perimeter) 702 of the device is where it ends and the natural skin 709 of the user is uncovered and exposed outside the device.
In FIGS. 21-29, the parts of the device under the points of most impact, under the heel, the metatarsal heads, and the big toe/hallux are cushioned/thickened areas 705 of the device. These areas are thicker than other portions of the device without increases thickness, e.g., the mid foot portion and portion between the big toe and forefoot area The device includes a back portion 720 adapted to engage the back of the foot behind the arch including the heel and ankle which includes a heel portion 710 adapted to engage at least the plantar portion of the heel of the foot, preferably also at least some of the sides (lateral and medial) and the back (posterior) of the heel, a middle portion 730 adapted to engage at least the arch of the foot, a front portion 740 adapted to engage at least the ball aspect of the foot at the metatarsal heads (the forefoot) and preferably sides of the forefoot, and a toe portion 750 adapted to engage at least one of the toes of the foot, namely the big toe and preferably the sides of the big toe. The device includes a medial side 798 and a lateral side 799.
The devices shown in FIGS. 21-25 and 27-29 are comprised of one silicone membrane 702 and one layer of silicone (gel-like) material 704 attached/connected to the silicone membrane 702 on the entire inner/upper surface of the silicone membrane 702. The inner/upper surface of the silicone layer 704 has a greater coefficient of friction and is tackier than the outer/lower surface of the silicone membrane 702. Preferably, the second silicone layer is of a lower durometer silicone than the silicone membrane, e.g., typically below the shore A scale and measured on the shore 00 scale. Silicones with physical properties in that category are ideal to provide adhesion onto the foot. The tacky inner/upper surface of the silicone allows it to remain in position without the use of adhesives or having to be attached to the footwear. A silicone membrane with, for example, a shore A 3-10 durometer, is preferable for its stretchability without deformity, and self-supporting properties that can act as a sufficient base layer for the lower durometer second silicone layer.
As shown in FIGS. 24 and 25, the device is pre-formed/molded to have a cupping elliptical surface 705 in cross section at the toe area 750 of the device to enable it to closely conform to the toe's bottom surface. The device has a pre-formed/molded cross section at the forefoot area 740 of the device comprising an undulating curvilinear shape consisting of two convex elliptical shapes connected in the middle by a concave elliptical shape. The device has a pre-formed/molded shape at the heel portion 710 of the device that consists of a ‘C’ cupping shape in both cross section and longitudinal section. The overall thickness of the device is such that not an unnatural amount of bulk is added under the wearer's foot. Additional thickness is added to the silicone membrane 702 at certain areas to compensate for the soft-tissue thickness reduction that occurs due to compressive forces acting on the toe, forefoot and heel during weight bearing activities such as walking and standing. The silicone membrane 702 is preferably less than about 3 mm at its thickest areas to prevent taking up too much room in the shoe and causing discomfort. The device, however, could be as thick as 4 mm at certain areas, such as the portion of the device in the front under the first metatarsal head (medial side of the device in the front area) to compensate for the compressed soft-tissue reduction that occurs at that region of the foot which is showed from research to typically be up to about 4 mm. In the most preferred embodiments, the device has the greatest thickness at the central most areas of the device at the big toe, forefoot and heel regions. The greatest thickness in the big toe region of the device is preferably between about 1.5 to 2 mm in the central portion thereof; the greatest thickness in the forefoot region of the device is preferably between about 1.5 to 3 mm; and the greatest thickness in heel area of the device is preferably between about 1 to 2 mm. The portions of the silicone membrane 702 between the areas of the device covering the major points of impact are about 1 mm thick. The edges of the silicone membrane 702 preferably taper or bevel to a thinner. Edges are preferably 0.5 mm thick but can be as thin as 0.25 mm, although silicone tears more easily at that thickness.
Preferably, the thickness of the second silicone layer (gel-like layer) 704 is less than the thickness of the silicone membrane 702. Preferably, the thickness of the second silicone layer 704 is between about 6-20 mils (about 0.15 to 0.5 mm).
FIG. 29 shows a sectional front view of the foot and device shown in FIGS. 21-28 taken in the forefoot portion also including a table showing example thicknesses of the device along its width from the medial side to the lateral side for the silicone membrane embodiments at the location of the greatest thickness. In all alternatives shown in the table, the thickness is greatest near the medial side of the device (the portion of the device under the first metatarsal head) and smallest near the lateral side of the device (the portion of the device under the fifth metatarsal head).
Alternative to the embodiment with a silicone membrane 702 covered by a silicone layer 704, the invention also includes a single silicone membrane 702 with differing friction characteristics on its two surfaces, the inner/upper surface and the outer/lower surface. The device can be molded out of a chosen, single, silicone durometer layer and achieve a contrasting tack/coefficient of friction on the surfaces by molding different surface textures. For example a low durometer, shore A 3 to shore A 10 material can be used to mold the silicone membrane with a polished surface finish for the inner/upper surface; whereas the outer/lower surface is molded with a texturized surface finish. This will provide a contrast in friction and tackiness as texturizing the surface of the silicone lowers the coefficient of friction and creates a surface that can more easily ‘slide’ over another surface; while providing a minor smooth finish to the silicone further creates a more tacky/high-coefficient of friction surface.
There are also coatings on the market that can reduce the coefficient of friction values of the outer/lower surface of the silicone membrane by about half or a range of 30-60 percent (from a 0.65 to a 0.31, for example). A talc powder can also be applied to the surface of the silicone membrane to further lower the friction values. Any of these methods may be utilized to achieve the optimal, lesser value of coefficient on the outer/lower surface of the silicone membrane. Enough slip is desired to adequately be able to slide the foot with the device on it into the footwear. At the same time, the device should not be too slippery with coefficient of friction values of 0.04-0.1, similar to those found in TPU film or a sheet of steel, which are very slippery, such that the user's foot slides to an uncomfortable degree forward in the footwear. The outer/lower surface of the silicone membrane is designed to have enough ‘bite’ and grip to keep the foot in place once the device and foot are placed into the footwear. Silicone creates this suctioning effect and helps grip the foot in the footwear to keep the device and foot in place and move more seamlessly with the shoe so that foot and shoe move as “one.”
The inner/upper surface of a single silicone membrane 702 can also include a second layer of silicone that is tacky and acts as an ‘adhesive’.
FIG. 26 shows an alternative embodiment of the device shown incorporated into an article of footwear 806 comprising a single silicone membrane 802 and under fill material 813 in the negative space between the membrane and the insole of the footwear including under the mid foot portion of the device, under the back side of the portion and the front side of the forefoot portion where those portions meet, and in front of the toe portion.
FIG. 27 shows an alternative embodiment of the device shown incorporated into an article of hosiery 906 comprising a single silicone membrane 902 and a lamination adhesive layer 906 to fasten the device to the hosiery 906.
FIG. 30 is a sectional front view of the foot at the forefoot area under a unloaded and loaded condition. The Figure also shows a section front view of the foot with the device according to the invention as shown in FIGS. 21-25 taken in the forefoot portion in a loaded condition. The Figure depicts the beneficial effects of the device on the foot, specifically the padding beneath the metatarsal heads of the user which provides supplemental padding to counteract the natural soft-tissue thickness padding reduction at this area, thus providing better support and comfort to the foot. The contouring/cupping action and direct, total contact that the device has protects/shields the foot's natural soft-tissue, so it does not as easily deform around the foot bones and stays in the form/shape that it naturally has prior to weight bearing activities (particularly at the bony prominences of the metatarsal heads). The device allows the foot's soft-tissue, therefore, to maintain its force dissipation/shock absorption properties. The device acts as a second-skin plantar aponeurosis (works in tension and compression) which contours and cups around and works alongside the foot's natural soft tissue complex 1) to prevent uncomfortable deformation/movement of the foot's natural soft-tissue padding around the foot bones and 2) help restore and/or provide supplementation padding thickness at the critical points of impact at the toe, forefoot and heel areas. The device works in both tension and compression to both move with and pad the foot, similar to the way in which the foot's own plantar aponeurosis works.
In addition the devices thickened areas at the forefoot, toe and heel resemble the way the foot's natural soft-tissue thicknesses are distributed. The invention provides added thicknesses/padding at the areas of the foot (toe, forefoot, heel) that make ground floor contact and are sustain a reduced thickness of the foot's natural soft-tissue padding due to compressive forces during weight bearing activities [such as walking and standing]. The reduced soft-tissue thickness is a phenomenon studied and known to particularly happen at the forefoot underneath the five metatarsal heads.
While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of applicant to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants' invention.

Claims

I claim:

1. A device to be worn on the foot comprising:

a base, unitary, self supporting, stretchable, membrane made of silicone having a durometer between about 3 and 10 on the Shore A scale configured in the general shape of the underside of a foot comprising a top surface, a bottom surface, a front, a back, an outer perimeter, a medial side and a lateral side; said membrane further comprising:

a cupped shaped toe portion in the front of the device having an indentation in a top surface configured to receive and contact the skin on the underside of a user's big toe when the device is worn;

a cupped shaped forefoot portion adjacent and connected to said toe portion, said forefoot portion having an indentation in a top surface configured to receive and contact the skin on the underside of a user's forefoot when the device is worn;

a midfoot portion adjacent to and connected to said forefoot portion; and

a cupped shaped heel portion adjacent and connected to said midfoot portion, said heel portion having an indentation in a top surface configured to receive and contact the skin on the underside of a user's heel when the device is worn;

wherein the thickness of said membrane in said toe portion is greatest near the center area of said toe portion and tapers down to a smaller thickness at the outer edge of said toe portion;

wherein the thickness of said membrane in said forefoot portion is greatest near the center of the forefoot portion and tapers down to a smaller thickness at the outer edge of said forefoot portion;

wherein the thickness of said membrane in said heel portion is greatest near the center of the heel portion and tapers down to a smaller thickness at the outer edge of said heel portion.

2. The device according to claim 1, wherein the thickness of said membrane in said forefoot portion is greatest near the medial side of the center of the forefoot portion and tapers down to a smaller thickness at the lateral side of said forefoot portion.

3. The device according to claim 1, wherein said thickness of said membrane in said toe portion tapers from between about 1.5 to 3.0 millimeters down to less than about 1 millimeter along the outer perimeter.

4. The device according to claim 1, wherein said thickness of said membrane in said forefoot portion tapers from between about 1.5 to 4.0 millimeters down to about 1 millimeter along the outer perimeter.

5. The device according to claim 1, wherein said thickness of said membrane in said heel portion tapers from between about 1.0 to 3.0 millimeters down to less than about 1 millimeter.

6. The device according to claim 1, wherein said thickness of said membrane in said midfoot portion has a thickness between about 0.25 to 1 millimeters.

7. The device according to claim 1, wherein said thickness of said membrane in said forefoot portion is greater near the medial side than it is near said lateral side.

8. The device according to claim 1, further comprising a smooth surface finish on said top surface of said membrane to increase the coefficient of friction and tackiness on said top surface.

9. The device according to claim 1, further comprising an adhesive coating on the upper surface of said device to increase the coefficient of friction and tackiness properties thereon.

10. The device according to claim 1, further comprising a second layer of silicone having an upper surface and a lower surface, said lower surface of said second layer of silicone fixedly attached to the upper surface of said membrane, said second layer of silicone having a durometer between about 20 to 40 on the Shore 00 scale.

11. The device according to claim 1, further comprising a second layer of silicone having an upper surface and a lower surface, said lower surface of said second layer of silicone fixedly attached to the upper surface of said membrane, wherein the durometer of said membrane is different than the durometer of said second layer of silicone.

12. The device according to claim 1, further comprising a second layer of silicone having an upper surface and a lower surface, said lower surface of said second layer of silicone fixedly attached to the upper surface of said membrane, wherein the coefficient of friction of the upper surface of the second layer of silicone is greater than the coefficient of friction of the lower surface of the membrane.

13. The device according to claim 1, further comprising a second layer of silicone having an upper surface and a lower surface, said lower surface of said second layer of silicone fixedly attached to the upper surface of said membrane, said upper surface having a coefficient of friction of at least about 0.75.

14. The device according to claim 1, wherein said membrane is a molded thermoset silicone rubber.

15. The device according to claim 1, wherein said membrane is a molded thermoplastic elastomer.

16. The device according to claim 1, further comprising a textured surface on said bottom surface of said membrane to reduce the coefficient of friction on said bottom surface.

17. The device according to claim 1, further comprising a low friction coating on said bottom surface of said membrane to reduce the coefficient of friction on said bottom surface.

18. The device according to claim 1, further comprising a talc powder on said bottom surface of said membrane to reduce the coefficient of friction on said bottom surface.

19. The device according to claim 1, adhered onto the foot portion of the exterior of an article of hosiery.

20. The device according to claim 1, attached inside an article of hosiery in the location where the user's foot rests.

21. A device to be worn on the foot comprising:

a base, unitary, self supporting, stretchable, membrane made of silicone configured in the general shape of the underside of a foot comprising a top surface, a bottom surface, a front, a back, an outer perimeter, a medial side and a lateral side; said membrane further comprising:

a midfoot portion adjacent to and connected to said forefoot portion; and

said device further comprising a second layer of silicone having an upper surface and a lower surface, said lower surface of said second layer of silicone fixedly attached to the upper surface of said membrane;

wherein said second layer of silicone has a durometer below the Shore A scale and measured on the shore 00 scale.

22. The device according to claim 21, wherein the thickness of said second layer of silicone is preferably between about 6 and 20 mils.