EMG - electromyography
EMG is often ordered when you have muscle weakness, pain or abnormal sensation. It can evaluate the health of the nerves and the muscles in the body outside of the brain and spinal cord.
What to expect
There are usually two parts to an EMG study.
- nerve conduction study
Your doctor will test the length of your nerves by delivering small electrical impulses and record responses from your sensory and motor nerves.
- The electromyography (EMG)
Your doctor will insert a very thin needle through your skin into the muscle. The electrode on the needle records the electrical activity given off by your muscles. This electrical activity appears on a nearby monitor and is heard through a speaker.
After the electrodes are placed in the muscle, you may be asked to contract the muscle. For example, you might be asked to bend your arm. The electrical activity seen on the monitor provides information about your muscle's ability to respond when the nerves to your muscles are stimulated.
Good for detecting
Muscle weakness, pain or abnormal sensation. It can evaluate the health of the nerves and the muscles in the body outside of the brain and spinal cord.
Good to know
You may feel some pain or discomfort during electrical stimulation or when the needles are inserted. Most people are able to complete the test without problems. After the test, the muscle may feel tender or bruised for a few hours to a few days.
Reviewed by: Ellie Madison
Last reviewed: 8/2/2018