- The elbow joint is actually composed of two separate articulations: the humeroulnar joint and humeroradial joint.
- The humeroulnar joint is formed between the trochlea of the medial distal end of the humerus and the coronoid process of the ulna.
- The humeroradial joint is formed between the capitulum of the lateral distal end of the humerus and the head of the radius.
- The humeroulnar joint is the functionally significant joint of the elbow joint complex.
- The elbow joint is a synovial, diarthrotic, uniaxial, hinge joint
- It allows:
- Flexion/extension in the sagittal plane.
NOTES:
- Also located with the synovial joint capsule of the elbow is the proximal radioulnar joint.
- We normally think of standard open-chain joint actions of the forearm moving relative to the arm at the elbow joint. However, when the hand is holding onto a stable object (i.e., is closed chain), then the arm must move toward the forearm. An example is doing a chin up.
- Pronation and supination of the forearm do NOT occur at the elbow joint; they occur at the radioulnar joints.