Is there a trade-off between economy and task goal variability in transfemoral amputee gait?

Only nine participants were studied, and all were already K3 full community ambulators who could walk at or above 0.8 m/s, so the results may not apply to new amputees or people who need handrails. Two participants held the handrails throughout the 1.4 m/s condition, which may affect gait variability at the fastest speed. The group varied widely in age, amputation side, time since amputation, and prosthesis type, and preferred walking speed was not recorded. Energy recovery rate was estimated from mechanical energy exchange, not oxygen consumption, and the authors note it may not accurately estimate energy cost, especially at faster speeds. The task goal was maintaining treadmill speed, which may not have been the participant's intended goal, so the goal-equivalent manifold may not reflect real-world walking goals.

No author conflict-of-interest declaration is included in the supplied text. The publication types list NIH extramural and U.S. Government non-PHS research support.

Do not read these results as proof that a powered prosthesis or gait training will improve energy economy. The study observed nine transfemoral amputees walking on a treadmill with passive prostheses and did not test an intervention.