Palmaris longus

Anatomy

Origin:
Medial epicondyle of humerus via the common flexor tendon.

Insertion:
Palmar aponeurosis of hand.

Key Relations:
One of the four muscles in the superficial anterior compartment of the forearm.

Functions

-Tenses the palmar aponeurosis, thereby anchoring the skin of the hand and resisting the shear forces in gripping. Its absence however has been shown not reduce the persons grip strength.
-Helps flex the hand at the wrist

e.g. as in gripping an object..

Supply

Nerve supply:
Median nerve (C6,C7).

Blood supply:
Ulnar artery.

Clinical

The muscle is absent in 20% of the population. In the remainder the muscle is a common choice for tendon transfer or grafting as no functional loss is apparent when it is used for this purpose.
Dupuytren’s contracture is a fixed flexion contracture of the hand where the fingers are bent towards the palm and cannot be extended fully. It is caused by an underlying contracture of the palmar aponeurosis.

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