AnatoMemory

Muscle

Palmaris longus

Absent in ~10-15% of people

Upper limbMuscular system

High-yield

Frequently absent; harvested for tendon grafts. Tensor of the palmar aponeurosis. Median nerve.

Overview

A slender, often-absent superficial flexor whose tendon tents the skin over the wrist and blends into the palmar aponeurosis.

Reference facts

Origin
Medial epicondyle of the humerus (common flexor origin)
Insertion
Flexor retinaculum and palmar aponeurosis
Action
Tenses the palmar aponeurosis and weakly flexes the wrist
Innervation
Median nerve (C7, C8)
Blood supply
Ulnar artery

Frequently asked questions

What does the palmaris longus do?

The palmaris longus tenses the palmar aponeurosis and weakly flexes the wrist.

What nerve innervates the palmaris longus?

The palmaris longus is innervated by the median nerve (C7, C8).

Where does the palmaris longus attach?

The palmaris longus originates from the medial epicondyle of the humerus (common flexor origin) and inserts on the flexor retinaculum and palmar aponeurosis.

What is the blood supply of the palmaris longus?

The palmaris longus is supplied by the ulnar artery.