With recent advances in clinical medicine and biomedical engineering, functional neuromuscular stimulation (FNS) can now be added to the physiatric armamentarium to decrease the debilitating effects of traumatic spinal cord injury. In this article, the components of FNS systems and their evolution in design are presented. The clinical implications of FNS are discussed with respect to upper and lower extremities and bladder applications, and perspectives on future developments and directions are reviewed.