At the elbow, the superior articular surface of the radial head spins on the capitulum while, at the same time, the articular surface on the side of the head slides against the radial notch of the ulna and adjacent areas of the joint capsule and anular ligament of the radius. At the distal radio-ulnar joint, the ulnar notch of the radius slides anteriorly over the convex surface of the head of the ulna. During these movements, the bones are held together by: the anular ligament of the radius at the proximal radio-ulnar joint, the interosseous membrane along the lengths of the radius and ulna, and the articular disc at the distal radio-ulnar joint (Fig. 7.83).