Electromyography (EMG) and nerve conduction studies are tests that measure the electrical activity of muscles and nerves. Nerves send out electrical signals to make your muscles react in certain ways. As your muscles react, they give off these signals, which can then be measured.
An EMG test looks at the electrical signals your muscles make when they are at rest and when they are being used.
A nerve conduction study measures how fast and how well the body's electrical signals travel down your nerves.
EMG tests and nerve conduction studies can both help find out if you have a disorder of your muscles, nerves, or both. These tests can be done separately, but they are usually done at the same time.
Other names for this test include electrodiagnostic study, EMG test, electromyogram, NCS, nerve conduction velocity, and NCV.