The opponens pollicis is one of the intrinsic muscles of the hand within the thenar group. It is the largest of the thenar muscles, and lies deep to the other two, the flexor pollicis brevis and the abductor pollicis brevis.

The intrinsic muscles of the hand are involved with precision movements and consist of the following muscles:

The intrinsic muscles of the hand are innervated by the deep branch of the ulnar nerve, except the tehnar muscles and the lateral two lumbricals. A mnemonic for remembering this is Meat LOAF, Meat = Median nerve innervates the Lateral lumbricals, Opponens pollicis, Abductor pollicis brevis and Flexor pollicis brevis

Origin
  • Tubercle of trapezium and adjacent flexor retinaculum
Insertion
  • Lateral margin and adjacent lateral palmar surface of the thumb metacarpal
Innervation
  • Recurrent Branch of Median Nerve

The recurrent branch of the median nerve supplies the thenar muscles. But remember that the deep head of the flexor pollicis brevis is supplied by the deep branch of the ulnar nerve.

The median nerve supplies sensation to the skin of the radial 3 and a half fingers (thumb, index, middle and lateral half of the ring).

The median nerve passes within the carpal tunnel and divides into the recurrent branch and palmar digital branches

Blood Supply
  • Superficial and deep palmar arch from the radial artery
  • Branches of first palmar metacarpal artery
Action
  • Flexes/opposition of the thumb – the movement of the thumb which allows the tip of the thumb to to touch the tips of the other fingers