when a nerve is stimulated, i.e., when sufficient electrical charge is provided to a nerve cell, a localized depolarization of the cell wall occurs resulting in an action potential that propagates toward both ends of the axon. typically, one "wave" of action potentials will propagate along the axon towards the muscle (orthodromic propagation) and concurrently, the other "wave" of action potentials will propagate towards the cell body in the central nervous system (antidromic propagation). while the direction of propagation in case of the antidromic stimulation and the sensory nerve stimulation is the same, i.e., towards the central nervous system, their end effects are very different. the antidromic stimulus has been considered an irrelevant side effect of fes. however, in recent years a hypothesis has been presented suggesting the potential role of the antidromic stimulation in neurorehabilitation. typically, fes is concerned with orthodromic stimulation and uses it to generate coordinated muscle contractions.