Prosthetic foot with tunable performance

Abstract

A prosthetic foot () incorporates a foot keel () and a calf shank () connected to the foot keel to form an ankle joint area of the prosthetic foot. The foot keel has forefoot and hindfoot portions and an upwardly arched midfoot portion extending between the forefoot and midfoot portions. The calf shank includes an anterior facing convexly curved lower portion which is adjustably attached at a portion thereof to the foot keel by way of a releasable fastener arrangement. The upper end of the calf shank is movable longitudinally of the foot keel in response to force loading and unloading the calf shank during use of the prosthetic foot. A device () connected between the upper end of the calf shank and the lower portion of the prosthesis can be used to assist posterior movement of the upper end of the calf shank and control anterior movement of the upper end of the calf shank during use of the prosthesis. The device () has springs which store energy during force loading with anterior motion of the upper end of the calf shank in gait and which, during force unloading, return the stored energy as kinetic power for adding to the propulsive force on the user's body generated by the prosthesis in gait.