To rotate the forearm so the palm faces downward.

To rotate the forearm so the palm faces downward.

• A. Supination
• B. Pronation
• C. Plantar flexion of the ankle
• D. Radiculopathy

Answer: (B)

Pronation is turning the forearm so the palm faces downward. In this movement the radius rotates across the ulna at the distal radioulnar joint, bringing the palm from facing up (anatomical position) to facing down. Muscles mainly responsible are the pronator teres and pronator quadratus. This is the opposite of supination, where the palm faces upward or forward, helped by the biceps brachii and the supinator. The other options describe movements or conditions unrelated to forearm rotation: plantar flexion is an ankle movement, and radiculopathy is nerve root pathology.

Pronation is turning the forearm so the palm faces downward. In this movement the radius rotates across the ulna at the distal radioulnar joint, bringing the palm from facing up (anatomical position) to facing down. Muscles mainly responsible are the pronator teres and pronator quadratus. This is the opposite of supination, where the palm faces upward or forward, helped by the biceps brachii and the supinator. The other options describe movements or conditions unrelated to forearm rotation: plantar flexion is an ankle movement, and radiculopathy is nerve root pathology.