Improvement of Gait When Using Above-Knee Prosthesis Fix/Extension Mechanism

Abstract

People lose knee joint when above knee is severed because of disease or accident. Losing knee joint makes people difficult to walk and to go up/down. Therefore, the range of activities of prosthetic wearers are decreased and the quality of life (QOL) for these people is lost. The walking gait obtained by almost all existing above-knee joint prosthesis are greatly different from healthy people because those prosthesis have no function of fixing/extending the knee joint at an arbitrary angle. This research develops an above knee developed which can fix and extend the knee with a compact and lightweight mechanism without using an external driving source for example batteries. In the proposed fixing mechanism, the wire is towed by the deformation of the arch type foot, and the brake-caliper clamps the brake disk fixed at knee joint, whereby the braking force is generated. In the knee extension mechanism, the input cylinder installed on the instep of the foot is pushed in, and extension torque around the knee joint is generated by extension of output cylinder connected by the hydraulic hose. In this paper, the gait stabilization is evaluated by forcusing on the ground reaction force and knee joint angle while using the developed above-knee prosthesis fix/extension.