A footwear or orthotic device, including a footwear or orthotic sole and an insert with an outer bladder having an uppermost surface curved concavely relative to an intended wearer's foot location in the device, as viewed upright and unloaded in a frontal plane. The outer bladder forms a component of the sole. An inner bladder includes a gas located inside and is substantially surrounded on at least the top, bottom and sides by the outer bladder. The outer bladder and inner bladder are separated by an internal sipe including a media. The sipe is formed by an inner surface of the outer bladder and an outer surface of the inner bladder. The 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 the surfaces forming the sipe are proximate to each other.