US Patent 7219449 Adaptively controlled footwear

A method for controlling footwear, comprising cushioning a transient force during use of the footwear at a first period of a gait cycle, storing energy from said cushioning, and releasing the stored energy during use of the footwear at a second period of the gait cycle, and after said transient force has subsided. The control can be electronic, mechanical or hydraulic, and is preferably dependent on a sensed gait cycle phase. The control may be adaptive to the user or the use of the footwear. The stored energy can be used to assist in locomotion, to generate electrical energy, to drive a heat pump, or simply dissipated.