USpring Design for Prosthetic Applications

A prosthesis, including a prosthetic foot, a prosthetic talocrural joint, a prosthetic ankle pivotally coupled to the prosthetic foot and a four-area bending beam. The four-area bending beam includes a U-shaped or other spring. One end of the spring is mechanically coupled via two of the four areas to the prosthetic foot. The other end of the spring is mechanically coupled via the other two areas to the prosthetic ankle. The spring resiliently resists pivoting of the prosthetic ankle about the prosthetic talocrural joint. The four-area bending beam exhibits an at least approximately constant moment along its length to maximize strain energy density, storing about four times as much elastic energy as a comparable cantilevered beam, thereby providing high stiffness and high range of motion to the ankle. The spring is modular, being easily replaced with another spring exhibiting a different stiffness, ex., to tailor the prosthesis to a user.