Patent ID: 7877897

Claim:
A shoe having an upper, a midsole, and an outsole, wherein said midsole comprises: a toe region, a middle region, a heel region, an upper layer, and a lower layer, wherein said upper layer has a bottom surface and said lower layer has a top surface, said lower layer being located substantially between the outsole and the upper layer, the bottom surface of said upper layer substantially facing the top surface of said lower layer, said bottom surface of said upper layer having a single longitudinal convexity and a single longitudinal concavity wherein the single longitudinal convexity occupies a substantial portion of the toe region and the single longitudinal concavity occupies a substantial portion of the heel region, said upper layer and said lower layer each having a durometer hardness wherein the durometer hardness of the upper layer is greater than the durometer hardness of the lower layer, and said upper layer having a durometer hardness greater than 60 on the Asker C scale.