radius

The radius is a long BONE of the FOREARM that extends from the ELBOW to the WRIST. It lies on the lateral or thumb side of the forearm when the hand is facing forward. Together with the ULNA, the radius supports movement of the forearm and allows rotation during actions such as turning the palm upward or downward. The upper end of the radius contributes to the ELBOW joint, while the lower end forms an important part of the WRIST joint.

The radius is the forearm bone on the thumb side that helps the arm and wrist move.

• One of the two bones of the forearm • Located on the thumb side • Extends between elbow and wrist • Works together with the ulna • Helps rotate the forearm • Important for wrist movement