Athletes with unilateral and bilateral transtibial amputations use carbon-fiber runningspecific prostheses (RSPs) to run. These devices consist of different model, stiffness, and height combinations. Since nearly all prior research has measured biomechanical and physiological effects of athletes with transtibial amputations using their own RSP(s), it is unknown how RSP characteristics affect the biomechanics and metabolic cost of transport of athletes with transtibial amputations during running.

Accordingly, the first aim of my dissertation was to quantify how prosthetic model, stiffness, and height affect the metabolic cost of transport of athletes with transtibial amputations during running. To accomplish this goal, I quantified RSP stiffness spanning multiple configurations of prosthetic model, height, and sagittal-plane angle. Then, athletes with unilateral and bilateral transtibial amputations ran 15 trials, each trial with a different RSP model, stiffness, and height configuration. These investigations demonstrated that prosthetic model, but not height, affects the metabolic cost of transport during running for athletes with unilateral and bilateral transtibial amputations. In addition, prosthetic stiffness affects the metabolic cost of running for athletes with bilateral, but not unilateral, transtibial amputations. Subsequently, I found that metabolic cost of transport is similar between athletes with transtibial amputations and non-amputees during running.

The second aim of my dissertation was to uncover how running biomechanics change across speeds for athletes with transtibial amputations. Initially, I assessed the influence of prosthetic stiffness and height on biomechanics across running speeds for athletes with bilateral transtibial amputations. I found that the influence of prosthetic stiffness on running biomechanics was mitigated at faster running speeds, whereas the influence of prosthetic height on biomechanics remained constant across running speeds. Next, I characterized the running biomechanics of the fastest athlete with a unilateral transtibial amputation across running speeds. In this study, I found that the fastest athlete with a unilateral transtibial amputation elicits running biomechanics that differ from athletes with bilateral transtibial amputations and nonamputees.

Overall, my dissertation indicates the importance of RSP configuration on distance running performance and sprinting biomechanics for athletes with transtibial amputations.