Abstract: An improved exercise device including a sole with an upper surface on which a wearer's foot rests and a lower partially ground contacting surface. The sole has a heel, a midfoot, a forefoot and a toe region such that when the heel region lower surface and the forefoot region lower surface are in ground contact, the upper surface does not incline upwards from the forefoot to the heel region. The forefoot lower surface of the sole is generally radiused in a cylindrical curve about the line connecting the mid points of the first and second metatarsal-phalangeal joints of the wearer. When the wearer contracts their calf muscles, the heel section is lifted away from the ground, requiring work against gravity.

Abstract: An improved exercise device including a sole with an upper surface on which a wearer's foot rests and a lower partially ground contacting surface. The sole has a heel, a midfoot, a forefoot and a toe region such that when the heel region lower surface and the forefoot region lower surface are in ground contact, the upper surface does not incline upwards from the forefoot to the heel region. The forefoot lower surface of the sole is generally radiused in a cylindrical curve about the line connecting the mid points of the first and second metatarsal-phalangeal joints of the wearer. When the wearer contracts their calf muscles, the heel section is lifted away from the ground, requiring work against gravity.

Abstract: The invention relates in part to a method of constructing a lasting board with contiguous attachment points. A flexible shoe lasting board is formed with extensions beyond the feather edge of the last. The extensions are coextensively formed with the lasting board since they are cut as a single unit from one sheet of material. This method of construction provides greater integrity of the joint between board and extensions than would be present if attachment was required, such as by stitching or cementing. The extensions of the lasting board are useful for securing the shoe to the foot and for securing components to the lasting board.

Abstract: An outsole for an item of footwear. The outsole is provided with a lower surface having a central portion and a peripheral portion. Also provided is one or more resilient shock absorbing strike plates which extend from, and are disposed about, the peripheral portion to define a cavity disposed below the central or peripheral portions. Each strike plate has an inwardly sloped wall adjacent the cavity. This sloped wall is disposed at an obtuse angle to the cavity. Also provided is an elastic membrane extending through the cavity. The membrane has a stiffness less than that of one of the strike plates to which it is connected.

Abstract: An article of footwear, for example, an athletic shoe designed for walking, running, or other sports activities. The article of footwear is provided with an upper, an outsole, and a midsole positioned between the outsole and the upper. The midsole has an upper surface upon which a sole of a foot is positioned during use of the article. The term "midsole" is meant to include any cushioning or other device placed within the footwear upon which a foot is positioned during use of the article. The midsole is also provided with an external cushioning spring. This spring includes an angled strip of resilient elastic material. One end of the strip is fixed on the surface of the midsole or outsole at a location at least 3 mm below the upper surface of the midsole. The other end of the strip is fixed on the surface of the midsole at least 3 mm vertically above the location at which the one end is fixed.

Abstract: An outsole for an item of footwear. The outsole is provided with a lower surface having a central portion and a peripheral portion. Also provided are a plurality of resilient shock absorbing strike plates which extend from, and are disposed about, the peripheral portion to define a central cavity disposed below the central portion. Each strike plate has an inwardly sloped wall adjacent the central concavity. This sloped wall is disposed at an obtuse angle to the central portion. Also provided is an elastic membrane connecting a plurality of the strike plates and extending through the central concavity. The membrane has a stiffness less than that of one of the strike plates to which it is connected.