Surface electromyography (EMG) is a diagnostic technique in which electrodes are placed on the skin and used to measure the electrical activity of the underlying muscle in response to electrical or nerve stimulation. The surface electromyography (SEMG) recordings, also referred to as the electromyogram, differ among patients and healthy persons and can be used to detect impairments in nerve and/or muscle function. The test has various applications in sports, ergonomics, rehabilitation, orthopedics, psychology, and neurology.