Electromyography
Electromyography
Electromyography, called "EMG", tests the electrical activity of the muscle at rest and flexed (contracted). Certain disorders, such as a pinched nerve, neuropathies, and muscle diseases, change the electrical activity of the muscles.
The testing involves the use of surface electrodes (small, round, metal disks) for nerve testing and small, fine needle electrodes for muscle testing. The electrodes are placed in different locations on your body and connected with small wires to a computer. The computer records the responses of the nerves and muscles on a chart called the electromyograph.
Nerve Testing
To measure nerve responses, the technician will touch a small, stimulator to your skin. This will produce a small, shock-like sensation. These stimuli are not harmful, but could be somewhat uncomfortable and re used to determine if the nerves are functioning correctly (receiving and sending messages to the brain).
Muscle Testing
When measuring muscle activity, a tiny disposable needle is inserted into the muscle being studied. When the needle is inserted, the computer records the muscle’s reaction. The "resting" activity is recorded first. In the next stage, you are asked to gradually increase the tightening or contracting of the muscle. During the test, the needle electrode may be moved to another part of the muscle.
Sine your muscles and nerves test better when you are comfortably warm, please tell the technician if you feel cool.
Getting Ready for the Test
For best results, bathe or shower the morning before the test, rubbing your arms and legs briskly with the cloth and soap to remove any oil from the skin. Do not use lotions or powder after your bath.
Tell the doctor if you are taking a blood thinner medication or if you bleed or bruise easily. Also, you should tell the doctor if you have a pacemaker, history of hepatitis or have been infected by the AIDS Virus. All precautions are taken to prevent any chance of AIDS or hepatitis infection to you and the technician.
The time needed for the test may be a few minutes or over an hour, depending on how many muscles and nerves are tested.
After the Test
Although you may have some discomfort afterwards in the area tested, this should not last very long. There are no after-effects or side-effects from this test.
Although you may have some discomfort afterwards in the area tested, this should not last very long. There are no after-effects or side-effects from this test.
The results of the test are studied by a neurologist who is a specialist in nerve and muscle diseases. The report of the findings will be sent to your physician who may discuss them with you.
Last modified: 2006-10-18
