New from Ability Dynamics is the Rush foot. The foot is made of a new composite fiber material, Flexeon, which is three times more flexible than carbon-fiber materials used in conventional prosthetic feet. The foot is designed for amputees with K3 and K4 activity levels, with a full rocker sole for above-knee amputees and a half rocker sole for below-knee amputees. The rStep connection between the upper and lower components creates a signature r-shape that propels each step. From midstance through terminal stance and toe off, the open design allows the forefoot and toe to flex in a natural way.