What to Expect During Your EMG Test

The following is a transcription of a pamphlet from the American Association of Neuromuscular and Electrodiagnostic Medicine ©2010.


What to Expect During Your EMG Test

Electrodiagnostic medicine is the study of diseases of nerve and muscles. Your doctor has recommended an EMG test to see if your muscles and nerves are working right. The results of the tests will help your doctor decide what is wrong and how it can be treated.

Types of Tests

  • Needle EMG

For this part of the test, a small, thin needle is put in several muscles to see if there are any problems. It is used once for each patient and is thrown away after the test. There may be a small amount of pain during this part of the examination. The doctor tests only the muscles necessary to decide what is wrong. During the EMG test the doctor will be able to hear and see how your muscles are working by the electrical signals made by your muscles. The doctor then uses his medical knowledge to figure out what could be causing your problem. 

  • Nerve conduction studies

NCSs show how well the body’s electrical signals are traveling to a nerve. This is done by applying small electrical shocks to the nerve and recording how the nerve works. These shocks cause a quick, mild, tingling feeling. The doctor may test several nerves. 

  • Evoked potentials

Evoked potentials are painless tests that check the nerve pathways through the spinal cord or from the eyes and ears. The signals for these tests can come from small electrical shocks, light pulses, or clicks of sound in the ears. The nerve responses are recorded over the scalp and other areas of skin. 

Answers to Your Questions

  • Why am I being sent to the EMG lab for tests?

You are being sent to the electromyography (EMG) lab because you have numbness, tingling, pain, weakness, or muscle cramping. Some of the tests that the EMG doctor may use to diagnose your symptoms are nerve conduction studies (NCSs), need EMG, and evoked potentials. The EMG doctor will examine you to decide which tests to do.

  • How long will these tests take?

The tests usually take 20 to 90 minutes. You can do any of your normal activities, like eating, driving, and exercising, before the tests. There are no lasting side effects. You can also do your normal activities after the tests. 

  • How should I prepare for the tests?

Tell the EMG doctor if you are taking aspirin, blood thinners (like Coumadin®), have a pacemaker, or have hemophilia. Take a bath or shower to remove oil from your skin. Do not use body lotion on the day of the test. If you have myasthenia gravis, ask your EMG doctor if you should take any medications before the test. 

  •  When will I know the test results?

The EMG doctor will discuss your test results with you and send them to your regular doctor. After the exam, check with the doctor who sent you to the lab for the next step in your care. 

  • What kind of medical training do doctors who do EMGs have?

Doctors who do EMGs go to 4 years of medical school then have 3 or 4 more years of training in a residency program. Most work as neurologists or physical medicine and rehabilitation doctors. Medical training helps the doctor decide which tests to perform based on your symptoms. It teaches doctors what can go wrong with the human body and how to tell the difference between these problems. 

  • Who does the testing?

The American Association of Neuromuscular  Electrodiagnostic Medicine’s policy is that an appropriately trained doctor should do all needle EMG testing. A trained assistant or technologist under a doctor’s supervision can do nerve conduction studies.


The  American Association of Neuromuscular  Electrodiagnostic Medicine (AANEM) was founded in 1953. It has more than 5000 physician members worldwide  The association aims o ensure quality patient care through education programs in research and quality assurance. 

2621 Superior Dr. NW

Rochester, MN 55901

For more information, visiting their website at www.aanem.org.

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