This blog post is intended for anyone who has been recommended to have a needle EMG exam that is
part of a “nerve test”. The information contained can also be helpful for health care professionals who
recommend their patients to have an electrodiagnostic examination.
I have been performing needle electromyography (EMG) exams for over 20 years. I have
encountered many types of people throughout the country, from corporate executives in midtown
Manhattan to undocumented laborers in Brooklyn and Queens to farm workers in rural areas of
Pennsylvania and Alabama. Across people of all backgrounds, the most common question people ask
me after I explain the procedure is “how much is this going to hurt?”. The goal of this article is to
address this concern.
Diagnostic tests are a common part of health care. X-rays, CT scans, MRIs, and ultrasounds give
providers information about the body’s internal structure. Blood and urine tests reveal clues on the
function of internal organ systems. Needle EMG exams are performed to describe the working status of
a person’s nerves and muscles. Of the above-mentioned tests, needle EMG exams are probably the least
commonly performed but also likely cause the most anxiety about the actual procedure of the test. This
is presumably due to the use of the needle. Needle phobia is a very real condition that is listed in the
American Medical Association’s tenth revision of the international classification of diseases. It is
estimated that 2 in 3 children and 1 in 4 adults have strong fears around needles. I recall that when I was
a small child, I dreaded going to the doctor and was told by my parents that it sometimes took multiple
people to stabilize my arm or leg when I would get a needle injection of medication or vaccine. Even
people without a fear avoid procedures using needles because they do not want the discomfort
associated with needles. Before I discuss some things that have been done to address the concern, I’ll
explain the use of the needle in diagnostic EMG tests.
Needle EMG tests examine the electrical signals produced by our nerves and muscles. These
biological types of electrical signals have much less voltage than those in machines. During a strong
contraction, a group of muscle fibers will normally have a voltage one million times smaller than a nine-
volt battery. A very precise instrument is needed to observe signals that small. While some of the
voltage can be detected through the skin, the skin itself dampens the signal that can be recorded. So, in
order to get the best measurement of the body’s electricity, the detection device needs to be inside the
muscle. Unlike needles that deliver medication or withdraw fluid, the needles used in EMG tests have a
very fine wire that is designed to detect the small electrical signal of the muscle. The proper amount of
electrical voltage is needed in our body’s nerves and muscles to allow us to feel things and to move our
body to do tasks. Even a slightly less amount of electricity than normal can be discovered in conditions
like carpal tunnel syndrome, sciatica, and amyotrophic lateral sclerosis also known as Lou Gehrig’s
disease. Being able to detect all of the electricity available is important to making the right conclusion.
Other differences between the use of needle in EMG and the use of needles in delivering medication or
withdrawing fluid include the size of the needle and how the needle is inserted into the body. Needles
used in EMG are relatively much thinner than needles used to draw blood. A needle’s gauge is the
measurement of the size of the diameter (how big around) of the needle, with a higher number
indicating a smaller diameter. The range of needle gauges used in needle EMG is 26 to 31 gauge, while
needles used in intramuscular injections are 22-25 gauge and the most common type of needle to do a
routine blood draw is 21. Unfortunately with needle EMG, because the size of the needle is so small, it
does need to be moved inside the muscle to measure a sufficient area of the muscle. This movement
can be associated with more discomfort. Needles for injection or fluid draw are stationary after entering the body. Lastly, during an EMG exam you do have to tighten the muscle in order to measure
the electrical activity of the muscle when it is contracting.
Healthcare providers like myself who perform needle EMG tests are aware of the discomfort of
the exam. There have been papers published in journals suggesting ways to help reduce the discomfort.
Buckelew and colleagues stated in 1992 that teaching active self-control skills and increasing patient’s
self-efficacy beliefs can help manage the anxiety and pain associated with needle EMG exams. They also
noted that reinterpreting the patient’s pain and judging the patient for their anxiety leads to more
discomfort. Strommen and Daube in 2001 discovered that the type of needle movement by the provider
plays a large role in the type of pain reported by the patient. Small, straight movements of the needle
are recommended. Stepping away from the healthcare and needle conversation for a moment, some
people prefer to know when something unpleasant is about to happen so they can better prepare
themselves. A theory for this rationale is that the bad event is less bad if they are ready for it. This
thinking has been applied to performance of needle EMG. A study from Australia in 2018 showed that
female patients who received written information about the procedure reported significantly lower
perceptions of pain from the EMG exam compared to those who got no information. Unfortunately, a
previous study from Italy in 2014 showed that a majority of patients received no information or
poor/incorrect information prior to the test. There are also recommendations on how to reduce
discomfort beyond educating the person getting the test or ways to move the needle. Tapping or
stretching the skin near the needle insertion site have been shown to be helpful. Providing distractions
such as videos, doing breathing exercises and devices that vibrate the skin can also be used. Lastly,
numbing creams and sprays or oral medications for sedation and pain relief can be considered.
However, the side effects of oral medications and the risk of infection from the skin numbing agent
entering the body along with the needle needs to be carefully considered.
Pain is something that is very difficult to measure and compare from person to person, so it will
be difficult to say how much the needle EMG will be perceived as painful for each person. In
professional sports, some athletes will miss field time from a blister while others can play with near
broken bones. Some people will seek out invasive procedures like tattoos or piercings while others will
be more reserved. There are strategies that providers can use to help minimize the discomfort and
things a person can do to mitigate or distract from the experience. There are also things healthcare
providers can do to make the experience more uncomfortable. In my own interaction with patients, I’ve
been told by some people that the way I do the test is much more comfortable than the test they had
from another provider or wasn’t as bad as they thought it was going to be. I’ve also been asked not to
return to some clinics because people have stated the test was uncomfortable. The act of inserting a
needle into the body is going to be uncomfortable. If you know that you do not deal with discomfort
well, you should try to take extra steps to mitigate the discomfort including seeking out a provider who
demonstrates compassion and discussing your concerns with the person doing the procedure. If you
and your referring provider agree that the information from the test will help you, then mentally
accepting temporary discomfort of the test might provide extremely useful information. To answer the
question in the title of this article, many things can influence how much discomfort you experience
during a needle EMG exam, including how you personally experience pain.
John Lugo, PT DPT
Board-Certified Clinical Specialist in Clinical Electrophysiologic Physical Therapy
Program Coordinator, EMG Solutions Residency Program
Site Coordinator of Clinical Education, EMG Solutions
References:
- Needle phobia diagnosis code: https://www.icd10data.com/ICD10CM/Codes/F01-F99/F40-
F48/F40-/F40.231 - Needle fears and phobias: https://www.cdc.gov/childrensmentalhealth/features/needle-
fears-and-phobia.html - Gauges of needles in EMG: https://www.ambu.com/Files/Images/ambu/clinical-
studies/Neuroline_EMG_Needles/Concentric-and-Monopolar-electromyographic-1211.pdf - Buckelew, S. P., Conway, R. C., Shutty, M. S., Lawrence, J. A., Grafing, M. R., Anderson, S. K.,
Hewett, J. E., & Keefe, F. J. (1992). Spontaneous coping strategies to manage acute pain and
anxiety during electrodiagnostic studies. Archives of physical medicine and rehabilitation,
73(6), 594–598. - Strommen, J. A., & Daube, J. R. (2001). Determinants of pain in needle electromyography.
Clinical neurophysiology : official journal of the International Federation of Clinical
Neurophysiology, 112(8), 1414–1418. https://doi.org/10.1016/s1388-2457(01)00552-1 - Lai, Y. L., Van Heuven, A., Borire, A., Kandula, T., Colebatch, J. G., Krishnan, A. V., & Huynh,
W. (2018). The provision of written information and its effect on levels of pain and anxiety
during electrodiagnostic studies: A randomised controlled trial. PloS one, 13(5), e0196917.
https://doi.org/10.1371/journal.pone.0196917 - Mondelli, M., Aretini, A., & Greco, G. (2014). Knowledge of electromyography (EMG) in
patients undergoing EMG examinations. Functional neurology, 29(3), 195–200. - London Z. N. (2017). Safety and pain in electrodiagnostic studies. Muscle & nerve, 55(2),
149–159. https://doi.org/10.1002/mus.25421
