Electromyography (EMG) measures and records the electrical activity of a muscle. It can record it at rest and when a muscle contracts.
An EMG is sometimes done studies that look at the electrical activity in your nerves.
An EMG can be done to:
Problems are rare, but all procedures have some risk. Your doctor will go over some of these problems, like:
Talk to your doctor about the medicines you are taking. You may be asked to make changes to them up to 1 week before the test.
On the day before and day of the test:
A small needle electrode will be placed into a muscle that is at rest. You will be asked to rest or tense the muscle. The activity picked up by the needle will make a waveform. It will be recorded and studied. The test will be done on other muscles and limbs.
You will be able to leave after the test is done. When you are home:
You may have some pain when the needle electrodes are placed. It feels like an injection into the muscle.
After the test, you may have muscle aches and discomfort for several days. Warm packs and pain medicine may help.
The doctor doing the EMG may talk about the results with you. A report will also be sent to your primary doctor. Your doctor will talk to you about options based on the tests and other factors.
After the test, call your doctor if you have:
Family Doctor—American Academy of Family Physicians
National Institute of Neurological Disorders and Stroke
Electromyography (EMG). Johns Hopkins Medicine website. Available at: http://www.hopkinsmedicine.org/healthlibrary/test_procedures/neurological/electromyography_emg_92,P07656. Accessed June 12, 2018.
FAQs before EDX testing. American Association of Neuromuscular & Electrodiagnostic Medicine website. Available at: http://www.aanem.org/Patients/FAQs-before-EDX-Testing. Accessed June 12, 2018.
Last reviewed May 2018 by EBSCO Medical Review Board Rimas Lukas, MD Last Updated: 6/12/2018