Supination is a rotational movement of the forearm at the radioulnar joint, or of the foot at the subtalar and talocalcaneonavicular joints.
When the arms are unbent and at the sides, the forearm is in supination when the palm faces to the front (anteriorly), or faces up. Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the lateral side of their feet (5th Metatarsal).
The hand is supine in the anatomical position. This action is performed by the Biceps brachii and the Supinator muscle.
Supination is the opposite of pronation.