Palmaris brevis

The palmaris brevis (Latin: musculus palmaris brevis) is a small quadrilateral-shaped muscle of the little finger. Although this muscle forms the hypothenar eminence together with the abductor digiti minimi, flexor digiti minimi brevis and opponens digiti minimi muscles, it has a minor function within the hypothenar eminence. Therefore, some authors do not classify this muscle as the hypothenar muscle. The palmaris brevis is the most superficial muscle of the ulnar hand side, and it extends between the fibrous structures of the hand and the skin of the hypothenar region.

Origin

The palmaris brevis muscle originates from the flexor retinaculum and palmar aponeurosis.

Insertion

The palmaris brevis inserts in the skin that covers the hypothenar area.

Action

Contractions of the palmaris brevis muscle wrinkle the skin on the ulnar side of the hand. Also, it tightens the palmar aponeurosis, increases grip strength and deepens the palmar fossa.

Innervation

The palmaris brevis is innervated by the superficial branch of the ulnar nerve. The ulnar nerve arises from the brachial plexus (C8, T1).

Blood supply

The palmaris brevis muscle receives arterial blood supply from the superficial palmar arch that is primarily formed by the ulnar artery.