Patent ID: 8291618

Claim:
A footwear or orthotic sole, comprising: an outer sole; and a footwear or orthotic device, the device including an outer chamber, compartment or bladder having an uppermost surface curved concavely relative to an intended wearer's foot location, as viewed in a frontal plane cross-section when the footwear or orthotic sole is upright and in an unloaded condition; at least one inner chamber, compartment or bladder inside said outer chamber, compartment or bladder; said outer chamber, compartment or bladder and said inner chamber, compartment or bladder being separated at least in part by at least a first internal sipe; and wherein said first internal sipe is formed by an inner surface of said outer chamber, compartment or bladder and an outer surface of said inner chamber, compartment or bladder; and the inner and outer surfaces forming the first internal sipe oppose each other and can move relative to each other in a sliding motion; and at least two layers of flexible, resilient midsole material are located within the at least one inner chamber, compartment or bladder, at least one layer of the midsole material including at least a plastic or rubber, and at least a second internal sipe is formed by opposing surfaces of said two layers of midsole material within the at least one inner chamber, compartment or bladder so that the opposing surfaces of said two layers of midsole that form the second internal sipe can move relative to each other in a sliding motion.