The Supination-Pronation Test for Distal Biceps Tendon Rupture.

Prompt diagnosis of a distal biceps tendon complete rupture increases the ability to perform a primary repair and to restore motion and strength. When examining an acute injury, it is important to isolate the biceps brachii tendon from the lacertus fibrosus and the brachialis because the examiner may mistakenly miss a distal tendon rupture by not isolating supination and pronation. The supination-pronation test can be performed easily in the acute setting and confirms attachment of the biceps tendon distally to the bicipital tuberosity of the radius. If the distal biceps tendon is intact, there is substantial change in the shape of the biceps as the arm is supinated (the biceps moves proximally), then pronated (the biceps moves distally). Clinically, the supination-pronation test has been found to be a reliable, pain-free test that should be incorporated in the physical examination to evaluate patients for distal biceps injury.