FOREARM LIFTER

摘要

A forearm lifter for assisting in the articulation of a mating forearm part of an arm prosthesis with respect to a mating upper arm part about at least one elbow axis is disclosed. The forearm lifter includes: (i) a spring element; (ii) a mechanism having an input and an output, with the spring element directly or indirectly applying a tensile force to the input of the mechanism; and (iii) a tension element having one end acted upon by the output of the mechanism, and having another end which can be fastened at a fixed point on said mating upper arm part. The fixed point and the elbow axis define a torque lever, such that the force that is transmitted through the mechanism from the spring element applies torque to the mating upper arm part in such a manner that the curve of the torque acting at the fixed point, plotted against the angle of articulation of said forearm part, is approximately parabolic. The torque has its minimum values in both the forearm extended position and at maximum forearm bending. The torque has its maximum value when said upper arm mating part and said forearm are at approximately 90.degree..