Elbow Joint

The **elbow joint** is a uniaxial hinge joint formed by the humeroulnar joint, where the trochlea of the humerus articulates with the trochlear notch of the ulna. The elbow also includes the humeroradial joint and the proximal radioulnar joint. All three joints are enclosed within a single articular capsule. This capsule is thin at the anterior and posterior aspects but reinforced along its outer edges by strong intrinsic ligaments that prevent side-to-side movement and hyperextension. On the medial side, the triangular ulnar collateral ligament provides stability, with its strongest portion, the anterior band, resisting elbow hyperextension. This ligament is susceptible to injury from frequent, forceful arm extensions, as seen in baseball pitchers. The lateral side of the elbow is supported by the radial collateral ligament, which originates from the lateral epicondyle of the humerus and integrates with the lateral side of the annular ligament. The annular ligament encircles the head of the radius, supporting it as it articulates with the radial notch of the ulna at the proximal radioulnar joint. This joint, a pivot joint, allows the radius to rotate during forearm supination and pronation. *LICENSES AND ATTRIBUTIONS CC licensed content, Shared previously Chapter 9. Authored by: OpenStax College. License: CC BY: Attribution. License Terms: Download for free at: http://cnx.org/contents/R3D4RG6w@4/Anatomy-of-Selected-Synovial-J.*