Palmaris longus muscle

PL Tendon

Grant 1962 97 D

Gray's anatomy image 417 color

== Palmaris longus muscle ==

The Palmaris longus muscle is a slender, superficial muscle of the forearm. It is one of the muscles of the anterior compartment of the forearm and is notable for its variability in the human population.

Anatomy

The Palmaris longus muscle originates from the medial epicondyle of the humerus via the common flexor tendon. It runs distally and inserts into the palmar aponeurosis and the flexor retinaculum of the hand. The muscle is innervated by the median nerve.

Function

The primary function of the Palmaris longus muscle is to tense the palmar aponeurosis, which helps in gripping objects. It also assists in flexing the hand at the wrist joint.

Variability

The Palmaris longus muscle is absent in about 14% of the population, with variations occurring bilaterally or unilaterally. The absence of this muscle does not typically result in any functional deficit.

Clinical Significance

The Palmaris longus muscle is often used as a donor tendon for various reconstructive surgical procedures due to its expendability. It is commonly harvested for tendon grafts in surgeries such as Tommy John surgery and ligament reconstruction.

Related Structures

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

See Also

• Forearm muscles
• Median nerve
• Palmar aponeurosis
• Flexor retinaculum of the hand