Fibrous Layer of Articular Capsule of Humeroulnar Joint
Stratum fibrosum capsulae articularis articulationis humeroulnaris
Read moreAnatomical Relations
The fibrous layer of the articular capsule of the humeroulnar joint forms the external layer of the articular capsule of the humeroulnar joint. The synovial membrane forms the internal layer of the capsule. Anteriorly and proximally, the fibrous membrane attaches to the medial epicondyle and just above the coronoid and radial fossae. It attaches to the edge of the coronoid process of the ulnar and the annular ligament, distally.
Posteriorly and proximally, the fibrous membrane attaches to the superior aspect of the capitulum, medial epicondyle, and the olecranon fossa. Distally, it extends to the superolateral margins of the olecranon and extends as the radioulnar capsule, attaching deep to the annular ligament (Standring, 2016).
Structure
The fibrous membrane of the humeroulnar joint is broad and thin anteriorly; it may receive fibers from the brachialis muscle and blends with the ulnar and radial collateral ligaments medially and laterally, respectively. Posteriorly, the fibrous membrane is even thinner than its anterior portion.
Function
The articular capsule of the humeroulnar joint ensures that the joint is sealed, thus, keeping the lubricating synovial fluid within the joint. It provides passive stability to the joint by limiting the joint movement. Additionally, it provides active stability but containing numerous proprioceptive nerve endings which relay mechanical information back to the central nervous system (Ralphs and Benjamin, 1994).
References
Ralphs, J. R. and Benjamin, M. (1994) 'The joint capsule: structure, composition, ageing and disease', Journal of Anatomy, 184(Pt 3), pp. 503-509.
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
