We are independent & ad-supported. We may earn a commission for purchases made through our links.
WiseGEEK

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 from 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.
Health

What is the Palmaris Longus?

By Alex Paul
Updated May 17, 2024
Our promise to you
WiseGEEK 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 WiseGEEK, 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.

The palmaris longus is a small muscle located in the wrist, although it is not found in around 14 percent of humans as there is some muscle variation with regards to ethnicity. Even though the muscle is associated with flexing the wrist there aren’t thought to be any negative side effects to not having a palmaris longus. The muscle is located between the flexor carpi ulnaris and flexor carpi radialis. As well as flexing the wrist, the muscle is also helps to tense certain muscles.

The origin of the palmaris longus is on the humerus. It originates from the common flexor tendon. The insertion of the muscle is at the palmar aponeurosis and finishes with a thin and flat tendon. Innervation of the muscle is via the median nerve.

Aside from the fact that the muscle is not present in some humans there is also some variation in how the muscle is presented. For example, some people may have a muscle that is tendon-like above and more muscular below. Some people may have a variation where the muscle is in the center while the tendon is found above and below. It is thought that none of the variations have any effect on grip strength.

One of the benefits of the palmaris longus being relatively unimportant is that it can be used for tendon grafts. A common wrist injury involves one of the tendons becoming ruptured. When this happens, the palmaris longus can sometimes be used to graft the tendon back together. The palmaris longus is also commonly used for this purpose due to its shape and size.

If the muscle and tendon are not present in a person who requires a tendon graft in the wrist then the tissue has to be taken from elsewhere in the body. If this is not possible then a tendon from a separate body must be used although this can cause problems due to a foreign substance being introduced into the body.

For example, in some animals the tendon is used to expose claws. It’s usually straightforward to discover whether a particular person has a palmaris longus muscle by flexing the wrist while pressing down on the base of the outer two fingers. If the muscle and tendon is present then it will be immediately visible through the skin. Although the muscle is not essential for humans, it is much more important for other animals.

WiseGEEK 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.
See our Editorial Process Share Feedback

Related Articles

Discussion Comments

By anon949270 — On May 04, 2014

I tore my mcl. This tendon is used to graph it. Is there anything that I may not be able to do without it? If so please respond.

By allenJo — On Feb 25, 2012

@SkyWhisperer - I hate to shoot down your theory, but it’s not borne out by the article. It’s clearly stated that there is no real use for the muscle.

So if there’s not much practical use, why would nature factor it in for the survival of a particular race? The impression I get from the article is that we can all live without this muscle and still go on our merry way.

If this is indeed the case, variations within the species should have no effect either way in my opinion. Although I would have to admit that it’s still curious why some people have it and some people don’t.

By SkyWhisperer — On Feb 25, 2012

@miriam98 - I’d be interested to know just who had this muscle and who didn’t. What races or ethnicities have the Palmaris longus muscle? If so, why? The same goes for those races that don’t have it.

My guess is that we are seeing here an example of natural selection at work. Perhaps some races live in regions of the world where such a muscle is not needed. The Palmaris longus function is deemed unimportant for the survival of the species and so that race develops without that muscle.

I’m not a scientist, but that’s my best shot at a theory.

By miriam98 — On Feb 24, 2012

This is the first time I’ve ever heard of a “spare muscle” so to speak, one that some people have and some people don’t. Nature is very creative here.

While I still don’t get the relative importance (or unimportance) of this muscle, I wonder if it can be used to cure or treat carpal tunnel syndrome or tendinitis.

Perhaps a Palmaris longus tendon graft can be used for muscular repair so that you can regain full use of your wrists or elbows which may have been injured due to repetitive stress or some sport.

Perhaps it’s already been done, I don’t know, but most stories I hear about carpal tunnel surgery focus on widening the existing muscle pathway, not attempting to rebuild tissues.

WiseGEEK, in your inbox

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

WiseGEEK, in your inbox

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