Nerve Testing for Chronic Foot Pain

What You Need To Know

How nerve testing helps identify the cause of pain, numbness, and weakness.

Understanding Nerve and Sensory Testing

Nerve and neurological sensory testing is performed using an electromyogram (EMG), which measures the electrical activity of muscles at rest and during contraction. Nerve conduction studies measure how well and how fast the nerves can send electrical signals.

Nerves control the muscles in the body with electrical signals called impulses. These impulses make the muscles react in specific ways, allowing your doctor to evaluate the responsiveness of the nerves and muscles. An abnormal response indicates a problem with the nerves and muscles, and may help to establish the specific nature of the issue.

A number of different things can cause muscle pain and numbness in the lower extremities. Poor circulation, diabetes, injuries, and other conditions can cause damage to nerves and muscles that impedes their ability to conduct signals and respond to impulses from the brain. A nerve sense test may be called for if you are experiencing symptoms of nerve damage or a nerve disorder, including tingling, numbness, weakness, spasms, or paralysis of the leg muscles.

If you have leg pain or numbness, these tests can determine how much your nerves are being affected. Our foot and ankle specialists will examine the foot, review your symptoms, and determine whether EMG or nerve conduction velocity (NCV) testing is appropriate. If you are experiencing any of these symptoms, contact Artisan Foot and Ankle Specialists to schedule an evaluation.

What to Expect During Your EMG

No major preparation is necessary for an electromyogram test. You should bathe or shower the day of the test, and your doctor may ask you not to use lotion or oil on the area being examined prior to the test, as some of these may interfere with results. You should also inform your doctor if you have a pacemaker or cardiac defibrillator, as electrical stimulation may affect these implants.

During the test, you will be asked to either lie down on a table or bed or sit in a reclining chair to relax your muscles. The skin around the testing area will be cleaned, and an electrode attached to a recording machine will be placed on the skin. Once the electrodes are in place, the electrical activity in your relaxed muscle is recorded by the machine.

The next step is to record the electrical activity in the contracted muscle, so your technologist will ask you to slowly tighten the muscle. To get a complete reading, the electrode may need to be moved several times. A video monitor shows the electrical activity as wavy or spiked lines, and you may also hear the activity on the machine. The EMG test usually takes 30 to 60 minutes.

There may be some mild muscle soreness following an EMG, but this should subside after a day or two. You will receive your results within a couple of days, and your doctor will work with you to put together a treatment plan based on the findings.