Patent ID: 8316558

Claim:
A shoe having an upper, a midsole, and an outsole wherein said midsole comprises: an upper layer and a lower layer wherein the lower layer has a bottom surface substantially adjacent to the outsole and a top surface substantially opposite the bottom surface of the lower layer, the lower layer being located substantially between the outsole and the upper layer, said upper layer having a bottom surface that substantially faces said top surface of said lower layer, said upper layer further having a heel region, said bottom surface of said upper layer further having at least a first convexity, a second convexity, and a first concavity, said first concavity occupying substantially all of said heel region of said bottom surface, and said upper layer and said lower layer each having a density wherein the density of the upper layer is denser than the density of the lower layer; said upper layer further having a toe region and a middle region and at least a substantial portion of said first convexity is located in said toe region and at least a substantial portion of said second convexity is located in said middle region.