Patent ID: 8567095

Claim:
A footwear or orthotic device, comprising: a footwear or orthotic sole; and an insert including at least one outer bladder having side portions, an uppermost surface and a lowermost surface, both said surfaces being curved concavely on both said side portions to define concavely curved side portions of the at least one outer bladder, so that said concavely curved side portions, together with a middle portion extending between the side portions, form said at least one outer bladder in a U-shape, the concave curvature and the U-shape being determined relative to a central portion an intended wearer's foot location in the footwear or orthotic device, as viewed in a frontal plane cross-section when the footwear or orthotic sole is upright and in an unloaded condition; said at least one outer bladder forming a component of the footwear or orthotic sole; and at least one inner bladder substantially surrounded on at least a top, bottom and sides by the at least one outer bladder, as viewed in a frontal plane cross-section, said at least one inner bladder including at least a gas located at least inside of said at least one inner bladder, said at least one outer bladder and said at least one inner bladder being separated at least in part by at least one internal sipe, said internal sipe including a magnetorheological fluid, wherein said internal sipe is defined by an inner surface of said at least one outer bladder and an outer surface of said at least one inner bladder; and the inner and outer surfaces forming the sipe oppose each other, are separate from each other and therefore can move relative to each other in a sliding motion; and at least a portion of each of said surfaces forming the sipe are proximate to each other in an unloaded condition.