küünarliigesega

The küünarliiges, commonly known as the elbow joint, is a complex hinge joint formed by three bones: the humerus, the ulna, and the radius. It allows for flexion and extension of the forearm relative to the upper arm, as well as pronation and supination of the forearm. The distal end of the humerus articulates with the proximal ends of the ulna and radius. Specifically, the trochlea of the humerus articulates with the trochlear notch of the ulna, forming the humeroulnar joint, which is primarily responsible for flexion and extension. The capitulum of the humerus articulates with the head of the radius, forming the humeroradial joint, which contributes to flexion and extension and also allows for rotation of the radius during pronation and supination. The proximal radioulnar joint, located between the head of the radius and the radial notch of the ulna, is crucial for pronation and supination movements. The entire joint capsule is reinforced by strong ligaments, including the collateral ligaments (ulnar and radial) and the annular ligament, which encircles the head of the radius. These ligaments provide stability and prevent excessive side-to-side movement. The muscles surrounding the elbow, such as the biceps brachii, triceps brachii, brachialis, pronator teres, and supinator, are responsible for generating the forces needed for movement at the joint. The elbow is a vital joint for everyday activities, enabling a wide range of arm motions.