Elbow anatomy, biomechanics and clinical examination

Abstract

The elbow joint is a complex articulation vital for upper limb function, combining stability with a wide range of motion in multiple planes. The joint consists of the three articulations: the ulno-humeral, radio-humeral and proximal radio-ulnar joints. These articulations are supported by several soft tissue stabilizers, which form the medial and lateral collateral ligaments, in addition to the joint capsule and annular ligament. The elbow joint is controlled by four main muscle groups: flexors, extensors, supinators and pronators. Numerous important structures cross the elbow joint: the brachial artery supplying the forearm, wrist and hand, and branches of the brachial plexus, principally the median, radial and ulnar nerves. The biomechanics of the elbow allow not only for flexion and extension of the elbow joint, but also supination and pronation of the forearm. The stability of the elbow joint whilst performing these movements is provided by the static and dynamic elbow stabilizers. The elbow joint is commonly assessed in OSCE examinations, and is assessed systematically through look, feel, move, and special tests.