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Supinator 2.png

Spinator is located in the posterior compartment of the forearm. It is the prime supinator of the forearm and has a broad origin from the ulna and humerus and extends down to the posterior surface of the proximal third of the radius. [1]



- Lateral epicondyle of the humerus

- Annular ligament

- Supinator Cest fossa of the ulna [2]


- Proximal third of the radius on the anterolateral surface, distal to the radial tuberosity. [2]

Nerve supply

Supinator is supplied by the posterior interosseous brach of the radial nerve (C5, C6) [3]


Supinator supinates the forearm. It causes the distal end of the radius to move anterolaterally around the ulna, causing them to lie paralell

Supinator works with biceps brachii if powerful supination is required. However biceps brachii is unable to function to supinate when the elbow is extended[3]



Place the patients arm in extension at the elbow and the forearm in midposition. Actively resist supination and palpate along the posterior part of the proximal third of the radius. [3]



  1. Drake RL, Vogl W, Mitchell AWM. Gray's anatomy for students. London: Churchill livingstone. 2005
  2. 2.0 2.1 Martini FH. Fundamentals of Anatomy and Physiology. Seventh Edition. Pearson Education Inc, 2006.
  3. 3.0 3.1 3.2 Palastanga N, Field D, Soames R. Anatomy and human movement. Structure and function. 5th ed. London: Butterworth Heinemann Elsevier, 2006