A patient’s guide to EMG testing
- Posted on: Jul 28 2017
How are EMG tests performed?
Electromyography (EMG) is a study that measures muscle and nerve response to electrical activity, used to identify neuromuscular abnormalities. The EMG procedure may be performed on an outpatient or inpatient basis.
These tests are performed in two ways:
- Nerve Conduction Study: This test examines how well the nerve is conducting a signal. NCS can detect nerve damage and can be performed at the same time as a needle EMG. A small electric shock is produced that will cause a mild tingling sensation and can be used to test serval nerves.
- Needle EMG: This test uses one or more small, thin needles (or electrodes) to examine the electrical signals of your muscles. The needle is inserted in several muscles of the affected area. The electrical activity is then picked up and displayed on a monitor that the doctor looks at and listens to the signals. The EMG is usually performed immediately after the nerve conduction study.
Why do I need an EMG?
An electro-diagnostic study is the only way to test if nerve damage exists and/or finding the causes of numbness, tingling, weakness, cramping, pain, or other loss of function. The doctor who performs these tests can tell if your nerves or muscles aren’t working efficiently. A negative test suggests that your symptoms are not dangerous and it’s safe to continue with conventional care. A positive test suggests that there is a problem with the conduction of the nerve or there is a muscle problem and further care should be administered. The test results will assist your doctor in establishing a proper treatment plan catered to your specific needs.
How long does it take?
An EMG/NCS test usually takes between 30 – 90 minutes. You may proceed with your normal activities once the test is performed.
How should I prepare?
Generally, abiding by these guidelines prior to your EMG test will best prepare you for the procedure:
- Alert the physician if you are on blood thinners or if you have a pace maker/imbedded defibrillator. Pain medication will not affect the results of this test, however, it is recommended that you bring a list of your normal medications with you.
- Avoid the application of body lotions or oils and take a shower prior to the study; this will ensure the adhesiveness of the electrodes to generate proper responses.
- Loose fitting clothing is recommended because it will allow for better access. The physician will also ask you to remove jewelry, hearing aids, or any other metal object that can interfere with the procedure.
Who will be performing my EMG test?
Doctors who do EMG testing go through 4 years of medical school and have another 3 – 4 years of training in a residency program. The American Association of Neuromuscular & Electrodiagnostic Medicine is that an appropriately trained doctor should do all needle EMG testing. A trained assistant or technologist under doctor’s supervision can do NCS.
What is the process like?
Generally, an EMG procedure follows this process:
- You will be asked to sit up or lie down.
- The physician or technologist will locate the muscle(s) to be studied.
- The skin will be cleansed with a solution and a fine, sterile needle will be inserted into the muscle. A ground electrode will be positioned under your arm or leg. More than 1 needle may be necessary for the test. You may experience a slight pinch with the insertion of the electrode. If the test is very painful, alert you your examiner.
- You will be asked to relax and contract your muscles.
- The electrical activity from your working muscle will be measured and displayed on the monitor.
Are there any side effects?
EMG tests are exceptionally safe; once the needles have been used on a patient, they are immediately disposed of. You may experience some muscle soreness for a couple of hours or so following the procedure. Notify your medical professional if you experience worsening pain, or swelling at the site of the needle injection. If you would like to learn more about EMG testing and other tools for healing nerve damage and muscle injuries, contact one of our 3 offices!