One of the most important aspects of treating pain conditions is getting down to the root cause of pain. An electromyogram (EMG) is a diagnostic test that can help you find your way to a diagnosis. Here’s what you should know about this diagnostic test.

What is an electromyogram?

An electromyogram (EMG) is a test of the electrical activity in your muscles and nerves. There are two aspects of this test: the first is the muscle test (the actual electromyogram). The second tests your nerves, specifically the peripheral motor nerves and the sensory nerves. This second test is called a nerve conduction study, or NCS. When someone refers a patient for an EMG, common usage of the term incorporates both tests.

When your nerves come out of the spinal cord, they are called nerve roots. From there, they divide into nerve branches that become peripheral nerves. This diagnostic procedure is usually ordered when certain symptoms arise. For example, if you have pain, numbness, burning, weakness, tingling, or other symptoms of nerve irritation, they may be coming from an injury to either your peripheral nerves or a nerve root.

Pressure on the nerve roots can also cause radiating, nerve-like pain that can occur with certain conditions. These include:

In simple terms, if a person has a pinched nerve in the spine or an extremity, an electromyogram can determine:

  • Where it is pinched
  • How severely it is pinched
  • If there is evidence of permanent or temporary damage

It can also distinguish between an injury to different types of nerves. Another use of electromyogram is to differentiate nerve trauma from nerve disease.

The value of the testing is to accurately determine location and severity of the injury. When this information is given to your doctor, they can then determine the best course of your treatment. And, if the electromyogram measures normal nerve activity, then the problem lies elsewhere.

How does an electromyogram work?

An electromyogram is a very safe diagnostic exam that uses electrodes on the skin to measure electrical activity. Before you have the procedure, shower to remove any lotions or oils on the skin that might prevent good contact with the electrodes. If you are able, wearing shorts and a short-sleeved shirt may mean you do not need to change into a surgical gown.

You will lie down on an examination table and have electrodes placed. Your neurologist may opt for needle electrodes, in which case a topical anesthetic may be applied to minimize your discomfort. Once the electrodes are in place, the neurologist performing the test will ask you to contract and release muscles or change positions.

The test typically takes between 20-30 minutes, depending on the complexity of the test and number of locations being monitored.


The electromyogram procedure is very safe. If needle electrodes are used, you may experience some bruising, but this should resolve quickly. Some patients feel minor sensitivity where electrodes are attached, but this is rare.

There is no recovery period, and you can return to your normal activity the day of the test. Your electromyogram report will be completed on the same day as your test and sent to your referring doctor within 24 hours. You’ll be able to speak with your physician about the result of your EMG at your next visit.

Learn more

An electromyogram test can be a useful diagnostic tool.

If you are experiencing symptoms of nerve irritation or damage, get in touch with Arizona Pain today for an evaluation and individualized plan of therapy.

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