When Fillauer came to us with a prototype of a new technology in prosthetics, we were excited and intrigued. The Element prosthetic foot employs a customizable carbon fiber spring called the “Third Element” which absorbs, stores, and returns energy in vertical and horizontal planes. It provides additional stability and agility, and since it can be tuned to the wearer, a more natural gait.

The whole foot works as a spring, so the curvature of each component dictates how the flex pattern is activated. An adjustment to a single curve would change the feel of the whole foot, which meant that any stylistic change would yield a functional change. Needless to say, designing this prosthesis required vigorous mechanical testing and analysis to make sure that it worked perfectly, for everyone, every time.

Our goal was in developing a design direction that mixed the functional aspects of walking with lines that were visually appealing. Along with adapting the curvature, and length of segments we made changes to the method of assembly. While the initial prototype contained the tunable Third Element, the way that it was attached did not allow optimal torsion. In a prosthetic foot, torsion works similar to the ankle enabling the foot pad to land off to the side and flex in to flat contact with the ground. By moving the two mounting screws in line with the length of the foot, we were able to provide a more streamlined look with additional functionality.