Study of the Force Moment Acting on the Socket of A/K Prostheses (Application to Controlling Signals for Ascending the Staircase)

Abstract

This report deals primarily with forces and moments such as two shearing forces (Fx, Fy), compression (Fz), two bending moments (Mx, My) and a torsional moment (Mz) that are acting on the stump of the thigh during walking. One above/knee amputee walked while wearing his A/K prosthesis which is equipped with the 6-axis force-moment sensor between the knee joint of the prosthesis and the socket, and measures the above-mentioned forces and moments. As a result of the walking experiments, the values of Fx, Fy, Fz, Mx, My and Mz during walking are determined. Also, the application of these forces and moments to controlling signals for ascending the staircase is described. The moment and the compression are utilized as triggers for extending or flexing the knee joint, respectively. The amputee wearing the A/K proshesis could ascend the staircase with a natural posture without the help of his arms. © 1991, The Japan Society of Mechanical Engineers. All rights reserved.