Abstract: “With a prosthetic device, people with a lower limb amputation can remain physically active, but most do not achieve medically recommended physical activity standards and are therefore at a greater risk of obesity and cardiovascular disease. Their reduced activity may be attributed to the 10 – 30% increase in energetic cost during walking compared to able-bodied individuals. Several active ankle-foot systems have been developed to provide external power during the push-off phase of gait, potentially alleviation this high cost. This talk will focus on the biologically inspired design of these devices, and several of our recent and ongoing projects exploring if and how people utilize external mechanical power to influence their metabolic effort, how this is influenced by the magnitude of power delivered, and the influence of the individual’s characteristics. I will then discuss our recent efforts to evaluate powered prosthetic technology in real-world environments.”