The Probert Encyclopaedia of Medicine

RADIUS

The radius is one of the two long bones (the other is the ulna) which form the lower arm (forearm). The radius articulates at each end with the ends of the ulna, with the humerus at the elbow, and some of the carpal bones at the wrist. When the hand is turned with the palm facing up (called supination), the radius is on the lateral (thumb) side of the forearm. When the hand is placed with the palm down (called pronation), the radius crosses over the ulna in mid-forearm.
Research Radius