Optimization of Six Bar Knee Linkage for Stability of Knee Prosthesis

The optimal design of human lower limb knee prostheses is fundamental in order to restore the lost functionality and aesthetic aspect of the amputee’s locomotion. The four-bar linkage is the most widespread mechanism, since, despite its simplicity, it allows the prosthesis to be sufficiently stable and, to replicate the natural motion of the joint with a sufficient accuracy. This work presents an optimization procedure for the synthesis of a six-bar linkage for knee prosthesis and its comparison with four-bar linkage counterpart. Different form of six bar linkages, such as Stephenson and Watt mechanisms are considered and optimized.