Author: Dr Peter de Souza
Last modified: 23 November 2022

The supinator is one of the muscles of the deep layer of the posterior compartment of the forearm. The supinator muscle wraps itself around the proximal radius enabling its function in supinating the forearm.

The posterior compartment of the forearm consists of a superficial layer (7 muscles) and a deep layer (5 muscles).

All the muscles of the posterior compartment are innervated by the radial nerve.

The muscles of the deep layer include:


2 heads – superficial and deep

  • Superficial (humeral) head: lateral epicondyle of humerus, annular ligament, radial collateral ligament
  • Deep (ulna) head: supinator crest and posterolateral surface of ulna


  • Lateral surface of proximal third of the radius – superior to the anterior oblique line and the insertion of the pronator teres


  • Supination of the forearm: rotates the radius to bring the palm facing anteriorly


Blood Supply

  • Superficial part – radial recurrent artery
  • Deep part – posterior interosseus and interosseus recurrent artery