Crossover Study of Kinematic, Kinetic, and Metabolic Performance of Active Persons with Transtibial Amputation Using Three Prosthetic Feet

Abstract

Introduction: This study was a double-blinded, randomized, repeated measures test of 14 persons with a unilateral transtibial amputation (TTA) walking and running on the Vari-Flex, Elite Blade, and the Re-Flex Rotate feet, with comparisons to persons without an amputation. The goal of the study was to compare ankle flexion, ankle moment, step length, ground reaction force (GRF), and metabolic cost of similar prosthetic feet for walking and running. Materials and Methods: Marker-based motion capture, GRF, and metabolic data were recorded, whereas participants walked and ran on a treadmill at self-selected speeds. Data were statistically analyzed for significant differences between conditions and groups using a multivariate analysis, with post hoc Tukey's test for multiple comparisons. Results: Plantarflexion was found to be significantly lower for prosthetic conditions than the contralateral and control conditions. Control participants had a shorter step length during walking. GRFs were generally lower for control and contralateral limbs. Heart rate, oxygen uptake, and self-selected speed were higher for TTAs than controls for walking and running. Conclusions: Differences between prosthetic feet included in this study were minimal. Although significant differences between TTAs and controls were found, these differences were confounded by the difference in self-selected speeds. (J Prosthet Orthot. 2021;33:110–117).