We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

How Do I Interpret My EMG Results?

By Jennifer Mackin
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Electromyography (EMG) is a medical test in which electrodes are inserted into a muscle to test for neuromuscular abnormalities. This is typically done to determine why a patient is experiencing muscle weakness or twitches, or a loss of feeling due to nerve compression. The results of EMG can be very difficult to interpret on your own. The results should be discussed with a neurologist, but understanding the basics can help you understand the doctor when he is explaining the EMG results.

Any muscle can be tested with an EMG. Each muscle has a normal range of electrical activity, also referred to as action potential, when it is in motion. This range usually depends on the size of the muscle and what it does. The EMG results are generally based around the normal range of the specific muscle being tested so, without knowing what is normal for that area of the body, deciphering the results on your own can be almost impossible.

For example, when you move, muscles fibers are activated to make that unique motion. Slight movements — like wiggling the fingers — activate fewer muscles fibers than stronger motions — such as clenching the hand into a fist. The more muscles fibers used, the more electrical activity the electromyography should record. The analysis of the entire test is then based on such motions and results.

A muscle usually has a slight increase in electrical activity as the electrodes are being put into place. After that stimulation subsides, the electromyograph should not record any electrical activity coming from the muscle if it is not moving. If the EMG results show any recordable measurements while the muscles are not moving, it could be a sign of a problem.

Not only does each muscle have a normal range of electrical activity during movement, there is also a normal range for how long each one took to stop showing electrical activity once it ceased moving. Damaged nerves, neuromuscular junction disease, or degenerative muscle disease can affect the EMG results in different ways. For this reason, a doctor must carefully examine the outcome of the test.

Nerve damage or neuromuscular junction disease can be indicated if the EMG results show that the test recorded electrical activity when the muscle was at rest. Also, nerve damage can cause a muscle in motion to use double the normal range of electrical activity, and take longer for it to subside when the muscle is relaxed. Degenerative muscle disease can show the opposite, as in muscles that never reach the normal range of electrical activity per movement or display no electrical activity at all.

Nerve damage can occur due to carpal tunnel disease, a ruptured disc in the back, and pinching of the sciatic nerve. Degenerative muscles disease can include a condition called polumysitis, which causes inflammation in and weakening of the muscles. Some genetic disorders, such as muscular dystrophy, can also cause muscle degeneration.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.