Elbow Joint Flashcards
How is the elbow joint classified?
Structually, the joint is classed as a synovial joint, and functionally as a hinge joint.
Describe the articulating surfaces of the elbow joint
It consists of two separate articulations:
- Trochlear notch of the ulna and the trochlea of the humerus
- Head of the radius and the capitulum of the humerus
(nb: The proximal radioulnar joint is found within same joint capsule of the elbow, but most literature considers it as a separate articulation)
What movements occur at the elbow?
The orientation of the bones forming the elbow joint produces a hinge type synovial joint, which allows for extension and flexion of the forearm:
Extension: Triceps brachii and anconeus
Flexion: Brachialis, biceps brachii, brachioradialis
Note – pronation and supination do not occur at the elbow – they are produced at the nearby radioulnar joints.
Describe how stability of the elbow joint is achieved
Like all synovial joints, the elbow joint has a capsule enclosing the joint. This in itself is strong and fibrous, strengthening the joint.
The joint capsule is thickened medially and laterally to form collateral ligaments, which stablise the flexing and extending motion of the arm.
The radial collateral ligament is found on the lateral side of the joint, extending from the lateral epicondyle, and blending with the anular ligament of the radius (a ligament from the proximal radioulnar joint).
The ulnar collateral ligament originates from the medial epicondyle, and attaches to the coronoid process and olecrannon of the ulna.
What are the clinically important bursae of the elbow?
Intratendinosus: Formed within the tendon of the triceps brachia.
Subtendinosus: Found between the olecrannon and the tendon of the triceps brachii, reducing friction between the two structures during extension and flexion of the arm.
Subcutaneous: Found between the olecrannon and the overlying connective tissue.
Bursae are clinically important, as they can become irritated and inflamed, producing pain.
