Electrodiagnostic medicine is the medical subspecialty that applies neurophysiologic techniques to diagnose, evaluate, and treat patients with impairments of the neurologic, neuromuscular, and/or muscular systems. Qualified physicians are trained in performing electrophysiological testing and interpretation of the test data. They require knowledge in anatomy, physiology, kinesiology, histology, and pathology of the brain, spinal cord, autonomic nerves, cranial nerves, peripheral nerves, neuromuscular junction, and muscles. They must know clinical features and treatment of diseases of the central, peripheral, and autonomic nervous systems, as well as those of neuromuscular junction and muscle. Physicians also require special knowledge about electric signal processing, including waveform analysis, electronics and instrumentation, stimulation and recording equipment, and statistics.