A fundamental knowledge of muscle and nerve physiology is crucial to the understanding and appropriate application of neuromuscular electrical stimulation (NMES) for children. This report presents a brief discussion of the physiology and theory supporting the use of NMES, including explanation of various waveforms, factors influencing fatigue, and stimulus parameters. Precautions and contraindications for the use of NMES, specifically as they relate to the pediatric population, are highlighted. Also, various therapeutic applications and their rationale are introduced.