SummaryA comparison of the literature quantifying the energy expended during ambulation of healthy individuals and those with amputation of the lower extremity is difficult as study parameters and methods are inconsistent. However, the energy cost of ambulation is greater for amputees than for nonamputees. Ascending level of amputation appears to be associated with increasing metabolic demand. There appears to be a difference in energy cost of ambulation following different surgical procedures. The literature regarding energy cost of ambulating with different lower-extremity prostheses is equivocal, with the exception of the contoured adducted trochanteric-controlled alignment method (CAT-CAM) socket for above-knee amputees and the new energy-storing (Proteor™) foot for traumatic below-knee amputees, which may decrease energy expenditure during ambulation. Therefore, it is reasonable to recommend that energy cost of ambulation be considered when deciding on the most efficacious surgical procedure, and metabolic efficiency of gait be considered when selecting prostheses most suitable for lower-extremity amputees.Though limited research is currently available, it appears that training or physical conditioning for the lower-extremity amputee, particularly with cardiopulmonary or vascular insufficiency, may decrease the metabolic cost of ambulation. More research is needed regarding the benefits of aerobic exercise and the safest, most effective exercise regimens for reducing metabolic costs of ambulation in lower-extremity amputees.