by Editorial Staff and Contributors
Electromyography (EMG) measures and records the electrical activity of a muscle. The test can record a muscle's electrical activity at rest or during a muscle contraction.
An EMG is often done with nerve conduction studies. These studies can analyze the electrical activity in your nerves.
Reasons for Test
EMG is most often done to:
Possible Complications TOP
There are no major complications associated with this test.
What to Expect TOP
Prior to Test
Make sure you talk to your doctor about the medicines you are taking. You may be asked to adjust certain medicines up to a week before the test, such as:
On the day before and day of the test:
Description of the Test
A small needle electrode will be inserted into a muscle at rest. You will be asked to rest or contract the muscle. The electrical activity picked up by the needle will produce a waveform. The waveform will be recorded and analyzed. The test is repeated on different muscles and limbs.
You will be able to leave once the test is done. Once you are home:
How Long Will It Take?
Will It Hurt?
You may have some pain when the needle electrodes are inserted. The insertion feels like an injection into the muscle.
After the test, you may have muscle aches and discomfort for several days. Warm compresses and pain medicine may help.
The doctor doing the EMG may discuss the results with you. A report will also be sent to your regular doctor. Your doctor will discuss treatment options based on the tests and other factors.
Call Your Doctor TOP
After the test, call your doctor if any of the following occur:
National Institutes of Health
National Institute of Neurological Disorders and Stroke
Muscular Dystrophy Canada
Electromyography (EMG). Mayo Clinic.com website. Available at: http://www.mayoclinic.com/health/emg/MY00107. Updated August 2010. Accessed November 12, 2010.
What to expect during your EMG test. American Association of Neuromuscular & Electrodiagnostic Medicine website. Available at: http://www.aanem.o.... Updated March 2005. Accessed June 5, 2008.
Young RR, Hutton JT, Homan RV. Gait and movement disorders. American Academy of Neurology website. Available at: http://www.aan.com/. Accessed June 5, 2008.
Last reviewed [Under Medical Review] by Lawrence Frisch, MD, MPH
Last Updated: 9/26/2011