Neuromuscular electrical stimulation (NMES) involves stimulation of neuromuscular fibers with an electric current of sufficient intensity to cause a muscle contraction. In persons with cerebral palsy (CP), NMES may be used in a passive manner to strengthen muscles, with the goal of improved gait or other physical function. Functional electrical stimulation (FES) is a variant of NMES in which stimulation is applied in a task-specific manner while the patient is walking or executing some other physical task. FES is intended to have an orthotic effect during use and has the potential to have lasting effects on muscle function.