PROXIMAL RADIOULNAR JOINT Meaning and
Definition
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The proximal radioulnar joint is a pivotal joint located in the forearm that allows for the rotation of the radius bone (the larger of the two forearm bones) around the ulna bone (the smaller forearm bone). This joint is classified as a pivot joint due to its structure and function.
Anatomically, the proximal radioulnar joint is situated at the elbow, specifically between the head of the radius and the radial notch of the ulna. It is surrounded by a joint capsule that provides stability and secures the joint together. The movement at this joint is enabled by a ring-shaped ligament called the annular ligament, which completely encircles the head of the radius, holding it in place against the radial notch of the ulna.
Functionally, the proximal radioulnar joint allows for pronation and supination of the forearm. Pronation refers to the rotation of the forearm with the palm facing down, while supination refers to the rotation of the forearm with the palm facing up. These movements are pivotal in activities such as turning a doorknob, using a screwdriver, or throwing a ball.
In summary, the proximal radioulnar joint is a pivotal joint located at the elbow that allows for rotational movements of the forearm. It is formed by the articulation of the head of the radius with the radial notch of the ulna, and its function is crucial for various everyday tasks involving arm rotation and manipulation.
