When it’s not clear why you’re experiencing numbness, tingling, pain, weakness, or muscle cramping that doesn't go away, nerve conduction velocity (NCV) and electromyography (EMG) tests may be helpful. These electrophysiologic tests measure the electrical activity of muscles and nerves to assist your healthcare provider in diagnosing your condition and planning treatment related to nerve and/or muscle dysfunction.
These tests should only be performed by specially trained clinicians. At St. Claire, EMG/NCV tests are performed by a board certified specialist in clinical electrophysiologic physical therapy.
Testing consists of two components and will take about 20-90 minutes depending upon how many extremities are being tested. 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. If you desire, you are able to drive yourself to and from the appointment.
Nerve Conduction Studies (NCS)
During the NCS, a small electrical current will be applied to the nerve that may be causing your symptoms. This current will cause a quick, mild tingling feeling. NCSs show how well the body's electrical signals are traveling to a nerve to reveal nerve damage or dysfunction. Several nerves may need to be tested.
Needle Electromyography (EMG)
For this part of the exam, a small, thin needle is inserted into several muscles to record your muscles electrical activity at rest and when contracted. This component of the test may be more uncomfortable as you may experience a small amount of pain when the needle is inserted. The physical therapist only examines the muscles necessary to decide what is wrong.