Design of Mechanism and Preliminary Field Validation of Low-Cost, Passive Prosthetic Knee for Users With Transfemoral Amputation in India

Abstract

An estimated 230,000 above-knee amputees in India are currently in need of prosthetic care, a majority of them facing severe socio-economic constraints. However, only few passive prosthetic knee devices in the market have been designed for facilitation of normative gait kinematics and for meeting the specific daily life needs of above-knee amputees in the developing world. Based on the results of our past studies, this paper establishes a framework for the design of a low-cost prosthetic knee device, which aims to facilitate able-bodied kinematics at a low metabolic cost. Based on an exhaustive set of functional requirements, we present a prototype mechanism design for the low-cost prosthetic knee. The mechanism is implemented using an early stance lock for stability and two friction dampers for achieving able-bodied kinematics and kinetics of walking. For early-stage validation of the prosthesis design, we carry out a preliminary field trial on four above-knee amputees in India and collect qualitative user feedback. Future iterations of the mechanism prototype will incorporate an additional spring component for enabling early stance flexion-extension.