Functional neuromuscular stimulation (FNS) devices have been proven to have therapeutic effects as evidenced by the changes in both the voluntary and electrically assisted neuromuscular function and improvements in the condition of soft tissue. Several experiments are being conducted which records changes in humans and animals with spinal cord injuries with the aim of using conditioning methods to assess function after injury and to promote and guide recovery of function. A better understanding of the mechanisms of neural plasticity, achieved through human and animal studies, may help in the design and implementation of FNS systems that have the potential to produce beneficial changes in the subject's central nervous systems.