Study of adaptation in amputees

Abstract

A large fraction of above-elbow amputees choose not to use available "high-tech" motorized prostheses in favor of simpler body-powered prostheses. The goal of this thesis is to begin the process of finding which aspects of body-powered prostheses make them more popular than motorized prostheses. It is desirable to objectively compare different prostheses in order to test hypotheses about which aspects of a prosthesis most affect its performance. A comparison method is proposed based on an amputee's ability to adapt to changes in a familiar task while wearing different prostheses. Crank turning is examined as a task in which adaptation can occur. One non-amputee and one amputee subject were tested in a pilot experiment of a crank turning task. Each was allowed to become familiar with a basic crank turning task. A perturbation, in the form of an external, position-dependent torque about the crank axis, was then added. An exponential curve, asymptotically approaching a steady-state level of performance, is fit to the data that was taken during the perturbation. The amputee subject showed significant adaptation while the non amputee subject showed no clear adaptation pattern.