What percentage of the population has a palmaris longus?

The palmaris longus is a muscle visible as a small tendon located between the flexor carpi radialis and the flexor carpi ulnaris, although it is not always present. It is absent in about 14 percent of the population; however, this number can vary in African, Asian, and Native American populations.

Why palmaris longus is vestigial?

Research has indicated that the palmaris longus, a thin strip of muscle running between the wrist and the elbow, is absent from both arms in about 10 percent of humans. The muscle presumably functioned in grip, with some speculation that it was of particular importance for hanging.

What muscle inserts at the palmar aponeurosis?

Palmaris longus muscle

What makes palmar aponeurosis?

Palmar aponeurosis is the central part of the deep fascia of the palm which is a highly specialized thickened structure with little mobility. Pylogenetically the palmar aponeurosis is considered as the degenerated tendon of palmaris longus.

Are two palmaris longus rare?

Tendon of the Palmaris longus crosses the retinaculum and fans out as a flat sheet which eventually continues as palmar aponeurosis. Variations of PL muscle are not uncommon. It has been estimated that in about 11% of cases, they are found to be absent (2, 3).

Is it good to have palmaris longus?

The role of this muscle is to help with wrist flexion. The palmaris longus muscle is one of the most variable muscles of the body. Although in the upper limbs its function is considered insignificant, in the event of tendon grafting, it is considerably important.

Is the palmar aponeurosis fascia?

Is palmar aponeurosis a muscle?

The palmaris longus (PL) is a muscle of the forearm with a long distal tendon that is continuous with the palmar aponeurosis (PA). It is generally assumed that the muscle lies deep to the antebrachial fascia from origin to termination, but a detailed description is lacking.

Is the palmar aponeurosis a tendon?

What is the function of palmar aponeurosis in humans?

Function of palmar aponeurosis is mechanical. It firmly attach­es to the palmar skin allowing it to: Slow thickening and shortening of the palmar aponeurosis is a condition known as Dupuytren’s Contracture. It is more common in folks with Northern European ancestry.

What is the function of the palmar longus muscle?

Fibers attaching to the palmar aponeurosis tighten this fascial sheath during the muscle’s contraction, resulting in a weak flexion of the 2nd to 5th metacarpophalangeal joints as the aponeurosis is being pulled towards the wrist. Tightening of the palmar aponeurosis also contributes to maintaining the hand’s grip while holding certain objects.

How to thicken and shorten the palmar aponeurosis?

Slow thickening and shortening of the palmar aponeurosis is a condition known as Dupuytren’s Contracture. It is more common in folks with Northern European ancestry. Try this: Bring flexed (bent) fingers and thumb towards each other to form a cup in palm of hand. Tense the hand and tap the palm with fingers of the opposite hand.

Is the palmar fascia normal in Dupuytren disease?

The palmar fascia, which in Dupuytren disease is abnormal, is composed of thenar, hypothenar, and palmar aponeuroses; palmar is involved most often (Fig. 84.4 ). Normal anatomy has bands of aponeurosis.