Design for Improved Trans-Tibial Prosthetic Devices Using Four Bar Mechanisms

Currently available prosthetic devices for trans-tibial (below the knee) amputees allow a great deal of mobility, but they do not allow amputees to walk with a normal gait. Most designs utilize passive elements to approximate the complex nonlinear response of the foot and ankle. This paper outlines early work in the design of a hybrid passive/active prosthesis that uses the inherent nonlinearity of a four bar mechanism and the power of numerical optimization to more closely duplicate the function of the human foot/ankle complex during walking.