The palmaris brevis a thin small quadrilateral intrinsic muscle of the hand within the subcutaneous tissue overlying the hypothenar muscles within the palm.

It originates from the palmar aponeurosis and flexor retinaculum and inserts onto the dermis of the skin - in doing so, it acts to tense the skin of the hypothenar eminence upon contraction, during gripping action. This may help to protect the ulnar nerve and artery during repetitive gripping actions, and may also help to improve grip.

Origin
  • Flexor retinaculum and medial part of palmar aponeurosis
Insertion
  • Dermis on the ulnar border of the hand

It lies superficial to the ulnar artery and superficial terminal branch of the ulnar nerve

Innervation
  • Superficial branch of ulnar nerve
Blood Supply
  • Branches from the ulnar side of the superficial palmar arch
Action

Palmaris brevis acts to tense the skin of the hypothenar eminence upon contraction, during gripping action. This may help to protect the ulnar nerve and artery during repetitive gripping actions. It also deepens the hollow of the palm, which could improve grip.