Immobilization following spinal cord injury (SCI) results in muscle and bone loss below the level of injury, which ultimately predisposes to fracture at several sites throughout the legs and can lead to several medical complications that can devastate quality of life. There is a scarcity of research that has successfully implemented rehabilitation and/or exercise training interventions to preserve the musculoskeletal system during the acute phase SCI, or possibly reverse the muscle and bone loss that has already occurred in chronic SCI. This study will compare the effect of exoskeleton-assisted walking (EAW) training combined with transcutaneous spinal cord stimulation (tSCS) (EAW + active tSCS), to that of EAW + sham tSCS, on measures of muscle and bone health in a cohort of chronically injured motor incomplete SCI. A successful outcome would expand treatment options to improve musculoskeletal health over the lifetime.