Artificial limb with a joint that simulates a bicondylar joint movement

Abstract

Abstract A joint for an artificial limb which simulates a natural bicondylar joint such as a knee. It consists essentially of a pintle which articulates the upper and lower members and has a ball and socket connection at one end with both members and at the other end a non-slip rolling connection with one member and a journal bearing in the other member. The pintle is coupled to each member through a restraint or torque control unit such as a slipping friction clutch or a torsionally resilient unit. In the case of an artificial knee joint, the non-slip connection may either be with the tibia, in which case the axis of the pintle remains fixed relative to the femur and the tibia is twisted about its axis on the ball and socket pivot as flexion occurs; or the non-slip connection may be with the femur, in which case the axis of the pintle remains fixed in relation to the tibia but slews on the femur as flexion occurs. The relative proportion of tibial rotation to flexion is a function of the difference between the torques of the two couplings, whose characteristics at any point in the flexion/extension cycle can be varied by devices such as a one-way clutch, or cam control of the pressure of the slipping clutch.

Inventors

• 👤 A Helfet

Bibliographic Details