Abstract
In order to realize self-rehabilitation at home by user oneself for early recovery to improve QOL, this paper discusses the development of a spatial rehabilitation mechanism for ankle joint which can adapt to fluctuation of rotational axis of human joint while preventing exertion of unnecessary shearing force. Kinetostatic analysis of the mechanism was performed to achieve large-enough range of motion to establish practical rehabilitation treatment, and to evaluate amplitude of the residual shearing force caused by friction on cylindrical joints and the gravity. Compensation of the shearing force was achieved by adding passive coil springs on certain joints. Optimum spring constant and initial offset of each spring were determined based on the slope and offset of a line, fitted to the ideal force distribution obtained from the theoretical analysis. By adding springs on two cylindrical and one revolute joints, the shearing force was reduced by 80%.
