The palmaris longus
Palmaris longus · musculus palmaris longus
A slender wrist muscle that around one in seven people simply don't have.
What it does
The palmaris longus runs from the inner elbow to a tough sheet of tissue in the palm. It helps bend the wrist and tenses the palm, but it is weak, and losing it makes little difference to grip strength.
Surprising fact
Touch your thumb to your little finger and flex your wrist. If a thin tendon pops up in the middle, you have a palmaris longus; somewhere around 15% of people don't.
Why it matters
Because you can do without it, surgeons often borrow its tendon to repair other tendons or ligaments, such as the elbow ligament that baseball pitchers tear.
Nearby
Read more
Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.