US Patent 7793431 Energy recycling footwear

Footwear including a foot support member and a sole assembly, the sole assembly having a first end and a second end, comprising a plurality of separate insole segments attached to the foot support member for bending the sole assembly, an outsole portion forming the base of the sole assembly, and a plurality of springs engaged between the insole segments and the outsole portion. The springs are arranged in a continuous series across the sole assembly from the first end to the second end, such that the springs exert a constant rebounding force on and across the sole of a user in series throughout a pace cycle.