5441 Babcock Road Ste 301, San Antonio TX, 78240
Office: (210) 641-1394 | Fax: (210) 561-2846
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Electromyography (EMG) and Nerve Conduction Velocity (NCV)

Electromyography and Nerve Conduction Velocity are tests to evaluate the health and function of nerves and muscles in your limbs and spine. Both tests are performed at the Clinic.


A physician performs an EMG by inserting sterile pins with a microscopic electrode on the tip into certain muscles of the patient’s limbs or back. The test can be helpful in evaluating the causes of numbness, tingling, pain, weakness, fatigue, and muscle cramping.

NCV Test

A technologist will perform the NCV test by placing several electrodes on the appropriate limb and applying a mild electric stimulus to the site. The test is often done at the same time as an EMG, in order to detect or rule out muscle disorders.

Before an EMG/NCV test

A physician’s prescription is required before scheduling an EMG/NCV test. You will change into a patient gown to allow the physician and technologist better access to your limbs. The testing is performed while you lay comfortably on a bed and the length of time involved varies with the number of limbs evaluated.

During an EMG/NCV test

The EMG evaluates your nerve and muscle function. This is done by placing a small, sterile pin into the muscle. The physician will review the waveforms generated by your nerve input into your muscle. There is a pinching sensation associated with this. The pin is usually in for approximately 30 seconds in each site and some limb movement may be requested by the physician. The NCV evaluates the speed of your nerve function. This is performed by applying a small electric stimulus to the limb and measuring how fast it takes to travel the nerve and to create certain waves to form.

After an EMG/NCV test

After the test, the physician will briefly explain the findings. You may experience a mild discomfort in certain areas of your limb. This generally resolves within 30 minutes following the test. There are no restrictions or limitations following the testing. The physician that ordered the test will receive the report and discuss the results in more detail with you.