Palmaris brevis is a small, quadrilateral muscle within the palm of the hand. It is sited superficial to the hypothenar eminence.
It originates from the flexor retinaculum and the palmar aponeurosis. It inserts into the dermis of the ulnar side of the palmar skin, making it part of the panniculus carnosus.
Its actions are minor:
- wrinkle the skin on the medial side of the palm
- deepen the hollow of the palm
- by a combination of both actions, steady the grip on the palmar side of the hand
It is the only muscle supplied by the superficial branch of the ulnar nerve (C8, T1).