The palmaris brevis muscle lies just underneath the skin. In English it is referred to as the short muscle on the flat of the hand. The muscle begins at the flexor retinaculum and is attached to the dermis at the ulnar side of the palm. The superficial branch of the ulnar nerve provides motor functions. The palmaris brevis muscle strengthens the grip of the hand on an object and helps form the hand into a cup shape. Because it is attached to the skin, it also wrinkles the skin during the cupping motion. It protects the ulnar nerve and artery. The palmaris brevis muscle is occasionally not present. The anatomist and physician Giovanni Battista first described the muscle. The next extant mention of the muscle is by William Cheselden in an anatomical textbook he published in 1713. To find the palmaris brevis muscle, cup the hand. The muscle dimples the skin of the palm along the edge of the palm below the little finger. The muscle is under the dimple.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Palmaris brevis