Ankle-knee synchronous knee lock mechanism: a revision.

An ankle-knee synchronous mechanism in a new endoskeletal above-knee (A-K) prosthesis has been designed and a preliminary clinical study has been conducted. A revision of the knee mechanism which is mainly focused on the basis of reducing the energy cost of the prosthetic wearer has been developed. It provides multiple position of the knee lock. It also provides anterior placement of the knee joint and a synchronous motion with the ankle joint. It enables the prosthetic wearer to minimize the effect of hip extensor contraction, to stabilize the knee, and maximize the sense of security and to balance the body over the artificial limb through the stance phase of gait. It permits the amputees to assume various body postures which enable them to perform daily activities. A new concept for alignment of A-K prosthesis is accomplished by using a weight bearing line instead of a trochanter and ankle (TKA) line, especially for the short A-K amputees. Deletion of the inertia control mechanism becomes possible by simply inserting a bumper in the knee to prevent terminal impact at swing phase and a built in coil spring acts as a knee extension aid.