Thisarticle discusses the design and testing of a powered ankleprosthesis. This new prosthesis mimics nonamputee (normal) ankle moments duringthe stance phase of gait through the use of anoptimized spring loaded four-bar mechanism. A prototype prosthesis based onthe optimization was designed, fabricated, and tested. The experimental resultsachieved 93.3% of the simulated theoretical ankle moment giving substantialevidence that this approach is a viable in designing poweredankle prostheses
