What is the distal radioulnar joint?

The distal radioulnar joint is lower two articulation between the radius and the ulna of the bone in the human forearm. When the radius and ulna run in parallel, they meet where each bone expands at the highest and worst point - just below the elbow and just above the wrist. The upper intersection is known as the proximal radioulnar joint, while the lower intersection is known as the distal radioulnar joint, with a distal referring to the structure of the furthest from the trunk of the body. Both articulations are referred to as a swivel joint, a type of synovial joint in which the articulation surfaces of neighboring bones rotate around them. Therefore, a specific movement of the allowed distal joint is the pronation or rotation of the palm of the forearm.

In order to understand the function of the rotary joint, it must first be known to its structure. The rotary joint consists of a cylindrical bone - in this case the head of the ulna, which is shaped as the end of the baton - pressed against another bone that has a connected line of the ligament surrounding the first bone. Proximal Radioulnar jointIt has a real ligament ring attached to the uln, an annular ligament through which the bones of the radius slide like a finger across the ring, and inside this ring it can rotate the bone in both direction. Given that the rotation that occurs on the distal Radioulnar joint is a slightly different movement, but the distal articulation is structured somewhat differently.

At the bottom articulation of radius and ulna, just above the wrist, adjacent surfaces are the opposite of those on the proximal joint: the ulna cylindrical head, unlike the radius, is articulated by the Ulnar Notch radius. In this case, both are not held together by not Valán in the shape of a circle, but by Volar and the back of the Leigouments, horizontal ligaments that connect the front and rear aspects of the bones. The structure of the distal Radiouln joint allows the rotation of palm or pronation.

During the pronace, the muscles of the pronator and the pronator quadratus that are found in the sublimeOktí and which attach to the side or outer surface of the radius on the thumb side of the arm, pull and pull in into the bones. This causes the radius to rotate around the street or on its front to create both bones X. When the muscles are released, the bones turn around the other on the distal radiouln of the joint and return to their neutral, parallel position.