Functional electrical stimulation (FES) is a widely-used modality in the rehabilitation of individuals with SCI (Sampson et al. 2000; Wood et al. 2001). Similar to any non-noxious or noxious stimuli below the level of injury, FES itself may also lead to significant afferent stimulation and trigger the development of AD (Ashley et al. 1993; Matthews et al. 1997).