Palmaris longus muscle

Palmaris Longus Muscle

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Palmaris longus muscle

The Palmaris longus muscle is a thin, fusiform muscle found in the human forearm. It is one of the five muscles in the superficial group of the anterior compartment of the forearm and is known for its high variability among individuals.

Anatomy

The Palmaris longus muscle originates from the medial epicondyle of the humerus and inserts into the palmar aponeurosis, a thick connective tissue found in the palm. It is innervated by the median nerve, which is responsible for its flexion function.

Function

The primary function of the Palmaris longus muscle is to tense the palmar aponeurosis, assisting in the flexion of the hand at the wrist. Despite its small size, it plays a significant role in the fine motor control of the hand.

Clinical Significance

The Palmaris longus muscle is often used in tendon grafts due to its long, accessible tendon and the fact that its absence or removal does not significantly affect hand function. It is also a common landmark for surgeons and clinicians when locating the median nerve or the ulnar artery.

Variations

The Palmaris longus muscle is known for its high variability. It is absent in about 14% of the population, and this absence can be either unilateral or bilateral. The muscle can also vary in its size, shape, and exact location.

See Also

• Flexor carpi radialis muscle
• Flexor carpi ulnaris muscle
• Flexor digitorum superficialis muscle
• Flexor digitorum profundus muscle