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EMG test What to expect from EMG/NCV testing
An EMG test checks how well your nerves and muscles work. It is usually done together with a nerve conduction study, in which small electrodes on the skin record how fast a nerve carries a mild electrical pulse, which feels like a quick tap or snap. For the EMG part, a very thin needle electrode records muscle activity at rest and as you tighten the muscle. The whole visit takes about 30 to 60 minutes, you can go back to normal activities right after, and the results help show whether numbness, tingling or weakness comes from a pinched nerve, carpal tunnel or another nerve problem. For one example of how testing fits into a pain plan, see our post on chemotherapy-induced neuropathy.
Numbness, tingling, burning or weakness in an arm or leg often comes from a nerve, but an MRI only shows structure, not how a nerve is working. An EMG test fills that gap. Doctors order it to find out whether a nerve is pinched or irritated, where along its path the problem is, and how much it is affecting the muscles. This post explains what to expect at an EMG test, step by step. For how nerve testing fits with other tests, see our guide to finding the cause of chronic pain.
Why a doctor orders an EMG test
- Arm symptoms from the neck: pain, numbness or weakness that travels from the neck into the shoulder, arm or hand, as in the second video
- Leg symptoms from the back: sciatica-type pain, numbness or a weak foot
- Hand numbness: possible carpal tunnel syndrome at the wrist, or a trapped nerve at the elbow; see numbness and tingling in hands for the other causes
- Unexplained weakness or cramping that could point to a nerve or muscle disorder
The results help decide treatment, for example whether a pinched nerve in the neck is the main problem, or whether the wrist needs attention instead.
Two parts: nerve conduction study and EMG
The nerve conduction study
Small sticky electrodes are placed on the skin over a nerve and a muscle. A handheld stimulator, like the one in the third video, gives brief electrical pulses along the nerve, and the machine measures how fast and how strongly the signal travels. Each pulse feels like a quick tap or a static shock and is over in a moment. Slow or weak signals at one spot can show where a nerve is being squeezed.
The needle EMG
A very thin, sterile needle electrode is placed into a few selected muscles, one at a time. It records the electrical activity while the muscle rests and while you tighten it gently. Most people feel a brief pinch or ache, similar to a small injection, but nothing is injected. The pattern shows whether the muscle is getting normal signals from its nerve.
EMG test: what to expect on the day
- Before: shower and skip lotion or oil on your arms and legs, because it stops the electrodes from sticking. Wear loose clothing. Tell the office if you take blood thinners, have a pacemaker or another implanted device, or have a bleeding disorder.
- During: you lie or sit on the table while the physician tests the nerves and muscles linked to your symptoms. Cold hands and feet are warmed first, because cold slows the signals.
- Time: usually 30 to 60 minutes, depending on how many limbs are tested.
- After: you can drive and go back to work. A muscle may feel a little sore for a day, and small bruises can appear where the needle went in.
The physician explains the findings and what they mean for your plan.
What the results can show
An EMG test can show a pinched nerve root in the neck or lower back, a nerve compressed further down, such as the median nerve at the wrist in carpal tunnel syndrome or the ulnar nerve at the elbow, wider nerve damage such as neuropathy, or a muscle problem. A normal result is useful too, because it points the search toward joints, tendons or muscles instead. For neck-related arm pain, see our guide to chronic neck pain treatment; for nerve symptoms after a back or neck operation, see recovery after spine surgery, and for pain that lingers after any operation, see pain after surgery. Learn more on our EMG/NCV testing page.
More videos on EMG and nerve testing
More clips from our YouTube channel @precisioncaremedical showing nerve conduction testing on the arm and how it helps find a pinched nerve.
Related care at Precision Care Medical & Sports Performance
EMG/NCV testing near you
Looking for a nerve conduction study near me? EMG/NCV testing is done at all three Precision Care Medical & Sports Performance offices. For an EMG in Brooklyn, Ashley Marcus, MD sees patients at our Brooklyn office on Shell Rd, close to Brighton Beach, Manhattan Beach and Gravesend. For an EMG on Staten Island, Jake Stephen, DO sees patients at our Staten Island office on Richmond Rd, a short drive from New Dorp, Great Kills and Dongan Hills.
In Manhattan, Yuri Gordin, MD sees patients at the Precision Care Spine & Pain Center in Midtown Manhattan, near Turtle Bay and the UN Plaza and an easy trip from the Upper East Side, Spanish Harlem and Washington Heights. If the symptoms followed a work injury or a car accident, tell the office about your claim when you call. Request an appointment or call the office closest to you.
150 E 55th St, Suite 401, New York, NY 10022
(212) 840-0135
Questions patients ask
Does an EMG test hurt?
The nerve conduction part feels like quick taps or small static shocks. The needle part causes a brief pinch or ache in each muscle tested. Most people find it uncomfortable but manageable, and it stops as soon as the test ends.
How long does an EMG test take?
Usually about 30 to 60 minutes, depending on how many arms or legs need testing.
How should I prepare for an EMG test?
Shower and skip lotion on the day, wear loose clothing, and tell the office about blood thinners, a pacemaker or other implanted device, or a bleeding disorder.
What is the difference between an EMG and a nerve conduction study?
A nerve conduction study uses electrodes on the skin and brief pulses to measure how well a nerve carries signals. EMG uses a thin needle electrode to record the electrical activity of muscles. They are usually done together.
Can an EMG show a pinched nerve or carpal tunnel?
Yes. It can show whether a nerve is pinched at the neck or lower back, compressed at the wrist or elbow, or affected more widely, and how much it is affecting the muscles.
Where can I get an EMG test near me?
EMG/NCV testing is done at all three Precision Care Medical & Sports Performance offices:
- Brooklyn2781 Shell Rd, Suite 101, Brooklyn, NY 11223(718) 648-1234 · Get directions
- Staten Island1630 Richmond Rd, Suite 101, Staten Island, NY 10304(718) 339-7100 · Get directions
- Midtown Manhattan150 E 55th St, Suite 401, New York, NY 10022(212) 840-0135 · Get directions
Educational only, not medical advice. These videos and this article explain common problems and treatments in general terms. They are not a diagnosis or a treatment plan for you. Results vary from person to person. See a qualified clinician about your own symptoms, and call 911 or go to an emergency room for an emergency.
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