Electromyography, or EMG, involves testing the electrical activity of muscles. Often, EMG testing is performed with another test that measures the conducting function of nerves. This is called a nerve conduction study. Both tests are usually performed at the same time.
Muscular movement involves the action of muscles and nerves and needs an electrical current. This electrical current is much weaker than the one in your household wiring. In some medical conditions, the electrical activity of the muscles or nerves is not normal. Finding and describing these electrical properties in the muscle or nerve may help diagnose your condition. EMG may aid with the diagnosis of nerve compression or injury such as carpal tunnel syndrome, nerve root injury such as sciatica, and with other problems of the muscles or nerves.