BACKGROUND OF INVENTION

The present invention relates to footwear which promotes a natural motion of the foot by simulating a barefoot experience, and which more specifically relates to anatomically shaped footwear having flexible materials located at anatomically correct flexure locations.

The "barefoot" running trend in footwear is gaining in popularity, with many examples of footwear coming onto the market with variations of this minimalist theme. Market leaders have created an iconic platform - a thin rubber outsole and elastic textile uppers that are assembled with individual toe segmentation to create "fingers". Other brands have taken a similar approach without improving on the benefits delivered.

However, there are many problems with such "barefoot" running shoes, and their "fingers." The lack of cushioning and protection underfoot, combined with encouragement to users that they land on their forefoot (rather than their heels) increases the impact force and potential discomfort experienced by the wearer. Further, the radical design is a turn-off to many mainstream consumers, which limits the end use and wearing occasions. Essentially, the "fingers" design is too much, too fast - the extreme design changes in the footwear are more than what the average consumer can adjust to wearing right out of the box.

There's a need for "more shoe" than what's being offered for everyday use. This invention improves upon the "barefoot" running trend without utilizing "fingers," while still providing comfort benefits delivered in more standard running footwear.

Specific advantages and features of the present invention will be apparent from the attached drawings and the description of an illustrative embodiment of the present invention. SUMMARY OF INVENTION

A shoe is designed to enable unhindered natural foot motion between the foot and the ground. To begin the design process, the shoe is constructed with a cupped heel, a contoured arch, a radiused forepart and neutral heel/forefoot position to create a foot bed that anatomically cradles a wearer's foot. A soft, flexible strobel stitched insole is added, which utilizes encapsulated high resiliency foam. The outsole is sculpted to have rounded natural edges and an anatomically correct flex location toward the forefoot of the shoe where softer, more flexible materials are used. The outsole is further designed with harder, protective materials strategically placed in high ground-contact areas to deliver protection and support. An optional midfoot support element may be positioned between the insole and outsole to control torsional stiffness. Upper materials are selected to minimize restriction of movement and promote breathability.

Specifically, the insole may be constructed of a high resiliency foam, such as neoprene, polyurethane, SEBS, EBA or rubber. Preferably, these materials would have a hardness of between about IOC and 60C on an Asker C scale. The outsole is preferably constructed from rubber or polyurethane, in either single or dual compound areas. For example, a dual compound outsole may have high-traction compound at high ground-contact locations, and a wear-resistant compound toward the perimeter of the outsole. Preferably, the hardness of either or both of these compounds would be in the range of about 45 A to 75 A on a Shore A scale.

The sock liner is preferably comprised of a base foam, including EVA, polyurethane or blended co-polymers. Sock liner hardness would preferably be in the range of about 25C to 70C on an Asker C scale. An insert may be made of foam or gel, including: thermoplastic rubber, polyurethane or SEBS, with a hardness of between about 25C and 60C on an Asker C scale. The midfoot support element is preferably made from molded plastic, rigid EVA, or Texon/tuck board, with a thickness of between about 1mm and 3mm, and with a hardness of between about 5 OA and 90A on a Shore A scale

Such a construction allows for: (a) increased contact between the foot and shoe interior; (b) a flexibility improvement such that less foot force is required to bend the shoe; (c) an improved gait by enabling natural motion during walking; (c) promoting more midfoot versus heel strike; (d) reduced weight over conventional shoes; (e) and increased foot stimulation through more utilization of bones, tendons, and muscles during footstrike.

These and other objects and advantages of the present invention will become more apparent to those skilled in the art after considering the following detailed specification taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a three dimensional perspective view of a last, sock liner, strobel sock insole and outsole of the present invention.

It should be understood that the present drawings are not necessarily to scale and that the present embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should also be understood that the present invention is not necessarily limited to the particular embodiments illustrated herein. Like numbers utilized throughout the various Figures designate like or similar parts or structure. DETAILED DESCRIPTION

In the present invention, shoe construction is provided which improves comfort during running. As shown in FIG. 1, a shoe will include a last or "upper" 5, sock liner 10, strobel sock insole 18 and outsole 20. Outsole 20 is positioned on the underside of the shoe for engagement with a walking surface such as the ground, sidewalk, floor or other supporting surface. Preferably, the top surface of the outsole is shaped to conform to the bottom surface of the sock liner 10 and/or strobel sock insole 18. The sock liner 10, strobel sock insole 18 and outsole 20 may be secured to one another using any suitable attachment means including cement, adhesives, glue, welt and direct attachment constructions

For ease of reference herein, the foot of a human may be considered to have three regions: the forefoot region (area adjacent the toes), the midfoot region (area adjacent the arch), and the hind foot region (area adjacent the heel). As shown in FIG. 1 the sock liner 10 and outsole 20 similarly includes three regions substantially underlying the above-referenced corresponding three regions of the wearer's foot: the forefoot region 16, 26 of the sock liner 10 and outsole 20, respectively; the midfoot region 14, 24 of the sock liner 10 and outsole 20, respectively; and the hind foot region 12, 22 of the sock liner 10 and outsole 20, respectively. It should be understood, however, that the boundaries between the forefoot, midfoot and hind foot areas are not precise and that these terms should be interpreted loosely and with a great deal of flexibility. The ball of the foot is generally the area of the foot at the juncture between the metatarsal bones and the phalange bones. The sockliner 10 may include soft pad sections on the bottom thereof at the forefoot region 16, midfoot region 14 and/or hind foot region 12.

The midfoot region 14, 24 of the sock liner 10 and outsole 20 is preferably raised to underlie the medial arch of the wearer's foot, while the hind foot region 12, 22 is cupped to underlie the heel of the wearer's foot. The hind foot region 12, 22 is defined by the peripheral edges 13, 23 formed around the hind foot region 12, 22 from the medial side to the lateral side of the heel. The peripheral edge 13, 23 in the hind foot region 12, 22 forms a raised portion where it wraps around the heel of the wearer's foot. The forefoot region 16, 26 includes a radiused forepart and a neutral heel/forefoot position. The anatomically shaped and formed sock liner 10 and outsole 20 are thereby designed to reflect the natural shapes of the human foot. The shaped plantar surface topography maximizes surface contact with the wearer's foot and increases comfort. The midfoot region 24 of outsole 20 may include a support shank 28 having a stiffness which is higher than the rest of outsole 20 so as to properly provide arch support to the wearer. Support shank 24 may instead be positioned between outsole 20 and strobel sock insole 18.

The shoe is constructed to enable unhindered natural foot motion between the foot and the ground. A soft, flexible strobel stitched insole (or strobel sock insole) 18 is added, which utilizes encapsulated high resiliency foam. The strobe stitched insole 18 preferably includes a foam interior sandwiched between fabric layers on the top and bottom. The outsole 20 is sculpted to have rounded natural edges and an anatomically correct flex location toward the forefoot 26 of the shoe where softer, more flexible materials are used. The outsole 20 is further designed with harder, protective materials strategically placed in high ground- contact areas to deliver protection and support. An optional midfoot support element 28 may be positioned between the insole and outsole to control torsional stiffness toward the midfoot region 14, 24. Upper materials are selected to minimize restriction of movement and promote breathability.

Such a construction allows for: (a) increased contact between the foot and shoe interior; (b) a flexibility improvement such that less foot force is required to bend the shoe; (c) an improved gait by enabling natural motion during walking; (c) promoting more midfoot versus heel strike; (d) reduced weight over conventional shoes; (e) and increased foot stimulation through more utilization of bones, tendons, and muscles during footstrike.

Further, the overall dimensions of the present shoe as well as the specific shape and configuration of the various sections thereof are also subject to wide variations and may be sized and shaped into a wide variety of different sizes and configurations so as to be compatible with the size and shape of the particular footwear onto which the present structures may be mounted, or to conform with any space limitations associated therewith without impairing the teachings and practice of the present invention.

It is also understood that various modifications may be made to all of the various embodiments without departing from the spirit and scope of the present invention.

Thus, there has been shown and described several embodiments of a footwear which promotes a natural foot motion. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms "having" and "including" and similar terms as used in the foregoing specification are used in the sense of "optional" or "may include" and not as "required". Many changes, modifications, variations and other uses and applications of the present invention will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.