Not applicable
Not applicable
The present invention relates to a shoe that is easily constructed and provides greater comfort to the wearer without affecting the fit or style of the shoe.
In order to understand the prior art and the present invention, it is necessary to understand the anatomy of the foot and the basics of shoe construction.
The heel 20 of the foot (also known as the tarsus) includes the talus 21 and the calcaneus 22 bones. The rear lower surface of the calcaneus 22 has a slight protuberance 23 known as the calcaneal tuberosity.
Referring to
Referring also to
Human footwear is designed to protect the human foot. However, as currently designed, human footwear is imperfect in providing proper biomechanical support for the human foot.
Also depicted in
In prior U.S. Pat. No. 4,597,195 to Dananberg (the '195 patent), there is described a human shoe sole having an area of reduced support underlying substantially only the location of the first metatarsal head of the wearer's foot. As described in the '195 patent, providing an area of reduced support substantially only under the head of the first metatarsal encourages eversion and plantar flection of the first metatarsal head as weight shifts from the heel to the first ray. Thus, normal functioning of the foot for plantar flection and supination is encouraged with beneficial results for improved walking comfort and shock absorption on subsequent heel contact. Prior PCT application WO 2011/017174 A1 describes an improvement in a human shoe sole or insole in which a depression provided underlying the first metatarsal head in which the depression has its lowest point skewed to the medial side of center. Millions of pairs of shoes have been manufactured and sold incorporating relief under the first metatarsal head as described above.
The present invention provides improvements over current footwear products in terms of function and comfort. In one aspect, the present invention provides significant improvement in terms of biomechanical functioning of the footwear product, resulting in increased comfort to the wearer, by providing a shallow channel on the top side of a contoured insole or shoe insert, specifically under the 1st metatarsal shaft. In the heelward to toeward direction, the channel is rotated 4±1 degrees plantargrade, with the toeward end lower than the heelward end. In the lateral to medial direction the channel slopes down about 9±2 degrees. The channel is not symmetrical side to side either, but rather rotated 10±5 degrees clockwise on the left and 10±5 degrees counterclockwise on the right. The variation in rotation can be used to accommodate a variety of different types of feet, from high to low arches. In low arched feet, the rotation would be greater as there is far less metatarsal head plantarflexion-eversion. In high arch feet, the rotation would be at the lower end of the rotation, as the 1st metatarsal is already plantarflexed.
The shallow channel is located on the top side of a 2-6 mm thick insole, which is trimmed to end behind the metatarsal heads and with a small 1st metatarsal recess. The channel also may be formed in a full length insole where a “step-down” of between 2-4 mm is placed at the metatarsal head locations across the ball of the foot. The step-down or thinner area is towards the toes and the thicker section towards the heel.
Alternatively, the channel may be located on the top side of an insole which has a raised “dome” 2 to 6 mm high in which the highest point is located between the 1st and 2nd metatarsal shafts rearward of the first and second metatarsal heads, and which is trimmed to end rearward of the metatarsal heads and with a small 1st metatarsal recess. The channel also can be placed on a full length insole where a “dome” is placed behind the metatarsal head locations across the ball of the foot, and the insole extends back under the heel of the foot.
The invention also preferably includes modifying the heel area or heel cup area of footwear to reduce the pressure on the plantar fascia of the wearer as it travels from its attachment on the medial calcaneus to the proximate phalanges, as will be described below, and includes a slightly raised (0.5-2 mm thick) region forward a slightly hollowed or depressed heel cup region (1-3 mm deep), adapted to underlie the heel of the wearer. The hollowed or depressed heel cup region is asymmetrical with its lowest region located to the medial side of the heel, and has a forward extension on the heel cup medial side.
The foot supporting surface can be built into the shoe, i.e. by providing a contoured insole board. Alternatively, the modified foot supporting bed may be provided as a separate piece which may be applied at the factory, or applied by the consumer after-market. Moreover, in the case of molded sandals and flip-flops, the foot supporting surface can be formed integrally with or cut out of the foot bed forming the sandal or flip-flops.
Stated another way, the device may be formed integrally with the foot bed of the shoe, as a shaped insole, or as a separate device. As used herein, “device” is intended to refer to all three.
The device is left/right shoe specific, wherein the left and right shoe pieces preferably are mirror images of one another.
Further features and advantages of the present invention can be seen, in detailed description, taken in conjunction with the accompanying drawings, wherein:
As used herein the term “sole” and “insole” are used interchangeably. Moreover, a “sole” or “insole” may be an element built into or forming an integral element of a footwear product such as an insole board, or as a separate element including, e.g. a sock liner or a removable insole, and after-market insole device, and after-market heel device, or a custom or prefabricated foot orthotic which may be inserted into a footwear product post-manufacturer. The heel element also may be formed directly in the foot supporting surface of a shoe, i.e. such as in the case of a molded sandal or flip-flop.
In one embodiment, the foot supporting surface comprises a separate element or device. In such embodiment, the device may be sized and shaped to conform to the shape of the sock liner or insole board. Optimally, in such embodiment, the device is narrower than the sock liner when it is to be positioned under the sock liner. This narrower size allows the edge of the sock liner to be adhered to the insole board along the edges of the device of the invention. Depending on the style of the shoes this narrower configuration may be particularly desirable. In other embodiments, described below, the device may be formed integrally with the sock liner, foot bed or insole board, or in the case of a molded footwear product such as a sandal or flip-flop, formed integrally as part of the foot supporting surface.
The device has a depressed area adapted to underlie the heel of the wearer, shaped generally to accommodate the wearer's calcaneal anatomy. The heel cup includes a forward extension on the medial side, which functions to reduce pressure on the plantar fascia as it travels from its attachment on the medial calcaneus to the proximal phalanges.
Referring in particular to
Referring to
Channel 302 which has a maximum depth of 1-3 mm, can be located on the top side of a flat 2-4 mm thick insole, which is trimmed at its toeward end 304 to end just behind all 5 metatarsal heads channel 302 is deepest at its toeward end 303 to accommodate, in part, the 1st metatarsal head of the wearer. Channel 302 also can be formed in a full length insole where a “step-down” of between 2-4 mm is located at the metatarsal head locations across the ball of the foot. The thinner area is towards the toes and the thicker section towards the heel.
In other words, channel 302 is located on the top side of an insole which may include a “dome” 308, 2 to 5 mm high in which the highest point 400 is located to lie between the 1st and 2nd metatarsals, and which extends to just behind all 5 metatarsal heads and is widest and deepest at its toeward end 303, to accommodate, in part, the 1st metatarsal head of the wearer. Channel 302 also can be formed in a full length insole where the “dome” 308 is located behind the metatarsal head locations across the ball of the foot, and the insole extends back under the heel of the foot.
A similarly shaped channel 302A may be formed in a “quarter” length insole where the “dome” 308 is located behind the metatarsal head locations across the ball of the foot, and the insole is trimmed at its heel ward end before it reaches the thinnest point 202, as shown in
In such embodiment, a pair of alignment notches 400 may be added to aid with proper alignment in the shoe since in this embodiment the forefoot section cannot rely on the under heel section of the full length device for proper alignment.
The insoles described above may be used with street and sport footwear including sandals. As noted above, the insoles may be incorporated into an insole board at the time of manufacture, formed as a sock liner or as an aftermarket insole device or a custom or prefabricated (over-the-counter) orthotic for placing into a shoe by the wearer.
Preferably, the upper surface of the device is smoothly contoured, with no sharp transitions or edges that could contribute to discomfort. Specifically, the transition between the apices of the raised areas and the surrounding areas of the device are filleted and smooth.
Providing a loafer, sandal or flip-flop with a channel underlying the first metatarsal shaft as above described, and with lop-sided heel cup as above described, significantly increases user comfort, and improved the biomechanics of wearer on walking.
Various changes may be made in the foregoing invention without departing from the spirit of the scope thereof.