radioulnaris

The radioulnar joints are the articulations between the radius and the ulna. These joints are classified as syndesmoses, which are fibrous joints where bones are united by a band of fibrous tissue. There are three radioulnar joints: the proximal radioulnar joint, the distal radioulnar joint, and the interosseous membrane.

The proximal radioulnar joint is located at the elbow, where the head of the radius articulates with the radial notch of the ulna. This articulation allows for pronation and supination of the forearm. The annular ligament also plays a crucial role in stabilizing this joint.

The distal radioulnar joint is situated at the wrist, where the head of the ulna articulates with the ulnar notch of the radius. This joint is also essential for forearm rotation. The articular disc of the distal radioulnar joint separates the ulna from the carpal bones.

The interosseous membrane is a broad, flat sheet of fibrous tissue that extends between the shafts of the radius and ulna along their entire length. This membrane not only connects the two bones but also serves as an attachment site for muscles of the forearm and helps to distribute forces between the radius and ulna. Together, these three radioulnar articulations enable the complex movements of the forearm required for a wide range of activities.