Electromyogram (EMG)

What is an Electromyogram (EMG)

An EMG measures the electrical activity of the muscle during contraction and relaxation.

An EMG consists of two parts: nerve conduction studies and a needle examination. Nerve conduction studies are useful in detecting nerve-related problems, such as nerve entrapment (for example, Carpal Tunnel Syndrome), or more widespread nerve dysfunction.

The needle examination is useful for identifying problems arising from a "pinched nerve" in the spine, as well as diseases of the muscles themselves.

Both parts of the test are usually needed for the physician to obtain meaningful results. The results of this test help your doctor determine the cause of your symptoms and select the best treatment for you.

What happens during an EMG?

You will be asked to lie on an exam table, either on your back or stomach, depending on the muscles to be tested. Small, flat discs called electrodes will be taped to the surface of your skin. A small electrical current is used to stimulate the nerve. Since the level of electricity used during the test is very low (similar to that of static electricity), the test is very safe. Repeated small, short shocks of varied intensity are administered. Our technicians will view and record the electrical activity of your muscles on a small television-like screen at your bedside.

The second part of the test involves the insertion of a tiny teflon coated needle into various muscles.

Once the needle has been inserted into the muscle, our technician will ask you to relax and then to move in a certain way so the muscle contracts (shortens) and its electrical activity can be recorded. Each muscle to be studied will require the insertion of a needle, so you may be "stuck" more than once. The stimulation of the nerve and the prick of the needle will be slightly uncomfortable.

You can help by lying still and remaining as relaxed as possible. The technician will help you by responding to your needs for a rest, or to change positions.

The test will last from 15 minutes to one hour, depending on the number of areas to be tested.

How should I prepare for an EMG?

No special preparation is necessary and you do not need to fast. A technician will be with you throughout the procedure to perform the test. Please let our technician know if you have had a mastectomy, take blood thinners, or have a pacemaker.

Do I need to change clothes for the test?

This depends on the area to be tested. If you complain of symptoms in either the shoulder, neck, or lower back area, you will be asked to wear a gown. We recommend that you wear loose fitting clothing and, if possible, do not wear any jewelry.

Will I receive any medication?

No medication is necessary before, during, or after the test.

How will I feel after the test?

Your diet and activities should not be affected by the test. Please feel free to ask our staff at any time, should you have any questions concerning your EMG test, or other aspects of your care.

How will I get the results of my test?

The results will be interpreted by our neurologist and given to your doctor, or explained to you at your next appointment.

Which locations offer EMG testing?

EMG tests are conducted at our Golden Valley, Burnsville, Coon Rapids, Edina and Maple Grove offices. In addition, we provide services at most of the outreach locations that we visit.