supinasjon

Supinasjon, commonly anglicized as supination, is a rotational movement of the forearm that turns the palm to face forward in the anatomical position. In the context of the foot, supinasjon can describe a combination of inversion, plantarflexion and adduction of the foot, producing a high-arched appearance during gait. Supination is the opposite of pronation.

In the forearm, supination occurs at the proximal and distal radioulnar joints as the radius rotates around the ulna. The movement is mainly produced by the supinator muscle and, when the elbow is flexed, the biceps brachii; the pronator muscles (pronator teres and pronator quadratus) produce pronation, the counterpart movement.

Normal forearm supination enables everyday actions such as turning a doorknob or opening a bottle. Clinically, reduced or painful supination can arise from injuries or conditions affecting the radius, ulna, radioulnar joints, or their supporting structures, including radial head fractures, distal radioulnar joint injuries, or interosseous membrane damage. In the lower limb, abnormal foot supination can influence gait and predispose to lateral ankle stress, while excessive or insufficient suprination can accompany various overuse injuries.

The term derives from Latin supināre, meaning to turn upward or lie on the back; in Norwegian medical usage, supinasjon corresponds to the same concept of supination.