Energy costs & performance of transtibial amputees & non-amputees during walking & running.

This study compared energy costs and performance differences of walking and running for transtibial amputee (TTA) and matched non-amputee runners. TTA were tested with 3 prosthetic feet: traditional foot, SACH; general purpose, energy storing and return (ESAR) foot, Renegade; running-specific ESAR foot, Nitro. During walking, VO2 and gait efficiency (GE) were similar between prosthetic feet. VO2 was increased (21-33%) and GE was decreased for TTA compared to controls. Self-selected walking speed (SSWS) was slower for SACH (4-6%) compared to Renegade and Nitro but SSWS for TTA was slower (16-22%) than controls. During running, VO2 was increased (8-18%) and GE was decreased using SACH and Renegade, compared to Nitro. During running, VO2 was greater (9-38%), GE was decreased and SSRS was slower (17-30%) for TTA, than controls. VO2 peak was similar for controls and TTA using Nitro, but peak running speed was slower for TTA. In conclusion, during walking energy costs are mostly similar between prosthetic feet, but ESAR feet likely provide faster SSWS for TTA. During running, energy costs and performance are improved for TTA using Nitro. Nonetheless, for all prosthetic feet conditions, TTA demonstrated an energy cost and performance disadvantage during walking and running compared to non-amputee runners.