abstract
- Individuals with unilateral transtibial amputation (uTTA) using a passive-elastic energy storage and return (ESAR) prosthesis to walk have asymmetrical peak propulsive horizontal ground reaction force (hGRF) compared to non-amputees. Investigating and normalizing peak propulsive hGRF could be beneficial for individuals with uTTA who experience a greater metabolic cost of walking, and greater risk of developing secondary comorbidities compared to non-amputees. Use of the BiOM stance-phase battery-powered prosthesis can decrease peak propulsive hGRF asymmetry and the metabolic cost of walking compared to an ESAR prosthesis in people with uTTA. Moreover, providing individuals with uTTA feedback of peak propulsive hGRF could change peak propulsive hGRF and metabolic cost. 12 participants with uTTA walked at 1.25 m/s while using an ESAR and BiOM prosthesis and were provided with visual feedback of peak propulsive hGRF. We found that when participants used the BiOM, affected leg (AL) peak propulsive hGRF increased by 0.014-0.017 BW, peak propulsive hGRF asymmetry decreased by 9.4-16.3 percentage points and net metabolic power decreased by 0.16-0.26 W/kg compared to when they used an ESAR prosthesis. When participants were given visual feedback of peak propulsive hGRF, they increased AL peak propulsive hGRF and decreased peak propulsive hGRF asymmetry but incurred a greater metabolic cost when using either prosthesis. Our results suggest that future device designs should explore providing feedback of biomechanical variables and device control to the user during walking so that individuals with uTTA can more effectively use a powered prosthesis.