To date, providers and patients have tolerated the limitations of these approaches due to the fairly simplistic goal of lower limb amputation: to provide a stable, padded surface for prosthesis mounting. Historically, lower limb prostheses have afforded amputees the opportunity to recover at least some measure of ambulatory function. Standard lower limb prostheses currently afford the wearer the walk in a rudimentary fashion, as well as occasionally run. However, such devices have generally not been able to recapitulate the complex biomechanics of the human lower limb due to limited ranges of motion and lack of feedback control. These limitations have resulted in substantially altered kinematics in lower limb amputees that are associated with derangements in energy expenditure profiles that worsen with laterality and ascending level.