Energy costs and performance of transfemoral amputees and non-amputees during walking and running

Abstract

Background: Limited information is available concerning the effects of prosthetic foot components on energy costs and ambulatory performance for transfemoral amputees. Objectives: Compare energy costs (VO₂; gait economy) and ambulatory performance (self-selected walking speeds, self-selected running speeds, peak running speeds) differences during walking and running for transfemoral amputees and matched, non-amputee runners. Study design: Repeated measures. Methods: Transfemoral amputees were accommodated and tested with three prosthetic feet: conventional foot, solid-ankle cushioned heel (SACH); energy storing and return foot, Renegade; and running-specific energy storing and return foot, Nitro. Results: During walking, VO₂ was similar between transfemoral amputees but was increased compared to controls. Self-selected walking speeds were slower for SACH compared to Renegade and Nitro. For transfemoral amputees, gait economy was decreased and self-selected walking speeds were slower compared to controls. During fixed running speeds, transfemoral amputees ran using Nitro, and VO₂ was greater compared to controls. Transfemoral amputees ran at self-selected running speeds using Renegade and Nitro. Self-selected running speeds were slower for Renegade compared to Nitro. For transfemoral amputees, gait economy was decreased and self-selected running speeds were slower compared to controls. VO₂ peak was similar between transfemoral amputees and controls, but controls achieved greater peak running speeds and % grade. Conclusion: Energy costs were greater and ambulatory performance was lower for transfemoral amputees compared to matched, non-amputee controls for all prosthetic foot conditions. Clinical relevance Both types of energy storing and return feet may improve walking performance for transfemoral amputees by providing faster self-selected walking speeds. For transfemoral amputees interested in performing vigorous running (exercise and running competition), clinicians should recommend a running-specific energy storing and return foot.