Self-selected walking speed in individuals with transfemoral amputation: recovery, economy and rehabilitation index

Abstract

Purpose: The aim of this study was to investigate the influence of walking speed on the pendular mechanism, cost of transport, mechanical efficiency and mechanical work in adults with lower-limb amputation, compared to a control group.Methods: Observational, cross sectional study. Ten subjects from an amputee rehabilitation clinic, with the same prosthetic knee and foot and ten healthy subjects were selected to form the experimental and the control group, respectively. Tridimensional kinematics data and oxygen uptake were collected simultaneously at five speeds: the self-selected walking speed (SSWS), two speeds above and below.Results: In the experimental group, the cost of transport was higher than in controls. Contrary to controls, in experimental group the minimum cost of transport and the maximum recovery did not coincide to the SSWS, but were reached at the maximum speed of the protocol. The mechanical efficiency in experimental group was lower, while the external mechanical work and pendular transduction were higher than in controls.Conclusions: The clinical relevance of these results is the concept, also supported by other studies, that interventions headed to increase the SSWS in the experimental group also increase and optimise the energetic economy and the pendulum efficiency of their locomotion.