The palmaris longus is a slender, inconstant forearm muscle absent in roughly 14 percent of people with no functional consequence. When present its tendon is the most superficial structure at the volar wrist crease and is identified by opposing the thumb and little finger while flexing the wrist. It is the most commonly harvested expendable tendon in reconstructive surgery, used for ACL reconstruction, flexor tendon repair, and facial reanimation procedures.
| Origin | Medial epicondyle via the common flexor tendon |
|---|---|
| Insertion | Palmar aponeurosis and flexor retinaculum |
| Nerve Supply | Median nerve (C7, C8) |
| Blood Supply | Ulnar artery |
| Actions |
|
|---|
Its primary role is tensing the palmar aponeurosis during grip rather than moving the wrist, protecting the neurovascular structures of the palm from compressive forces during handling activities.
Checking for palmaris longus presence is a routine pre-operative step before any tendon graft procedure because its absence requires choosing an alternative donor site. When present, reversed palmaris longus syndrome occasionally causes carpal tunnel symptoms from a reversed tendon belly pressing on the carpal tunnel contents. Dupuytren disease involves thickening of the palmar aponeurosis into which the palmaris longus inserts.
When present, it is the central and most prominent wrist tendon visible during the Schaeffer test of opposing thumb and little finger while flexing the wrist, easily distinguished from the flanking FCR tendon laterally and the FCU tendon medially.
Rare inflammation producing central volar wrist pain reproduced by resisted wrist flexion, diagnosed only after excluding carpal tunnel, FCR, and FCU pathology as more common causes.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
