Electromyography (EMG) is a test of the health of muscles and the nerves that control them. EMG may be requested by your doctor if you have signs or symptoms of a nerve or muscle problem. These could include tingling, numbness, muscle weakness, muscle pain or cramping.
The first part of the test is called nerve conduction studies. In a nerve conduction study, electrode stickers are applied to the skin (surface electrodes) to measure the speed and strength of the nerve signals after light shocks to the skin.
During an EMG test, small needles about the size used in acupuncture are inserted into muscles to check for electrical signals that indicate damage to the nerve or muscle. A routine test might examine 3-6 muscles; it could be more, or the specialist might decide it is not necessary at all.
What to Expect
An EMG referral includes a comprehensive assessment by a Physical Medicine and Rehabilitation doctor (Physiatrist). The Physiatrist will ask questions about your symptoms, your past medical and family history, your medications and anything else that might be important. The doctor will also then perform a physical examination focusing on your nerves and muscles.
The test can be performed either by the doctor or by a technologist who specializes in the nerve conduction study tests. In general, you will be asked to sit or lie down with the arm or leg exposed. These tests are generally well tolerated by patients, but some people find them uncomfortable.
Appointments can last between 30 and 75 minutes depending on the complexity of your problem.
How to Prepare
- Please bring a list of your medications
- Wear clothes that allow easy access to the body part that will be studied. If symptoms are in the upper body, wear or bring a short sleeve shirt. If symptoms are in the lower body, bring a pair of shorts.
- Do not apply skin lotions or creams on the day of testing
- Please arrive 15-20 minutes before your appointment to allow time for parking and registration
- You may go about your regular daily activities (eating, working, driving, exercising, etc) before and after the test. There are no lasting side effects from the tests.