Radio-ulnar Joints – Joints of Upper Limb

00:01 So if we have a look at the radio-ulnar joint, the proximal radio-ulnar joint, then we can see the articulation is going between the head of the radius here and the radial notch of the ulnar. The joint capsule is continuous with the elbow. So the elbow joint capsule covers this joint as well. And we can see we have the annular ligament. This encircles the radial head. We can see it attaches to the anterior and posterior surfaces of the ulna. It’s passing all the way around the head. And this enables the radius to just rotate, rotate against the radial notch, which we can see here on the ulna. And this enables pronation and supination to occur. If we look at the distal radio-ulnar joint, the articulation of the distal radio-ulnar joint again is between the head of the ulna and the ulnar notch on the radius. So we can see we’ve got the head of the ulna here in this section through the wrist joint. To see it, we’ve got the head of the ulna and then we can see we have the ulnar notch on the radius here. And this connection would be your distal radio-ulnar joint, your distal radio-ulnar joint. We have a small articular disc that binds the joint together. So we’ve got the joint capsule coming around on the wrist and we’ve got this articular disc that’s binding, that’s holding the joint together. We can see the articular disc has been slightly reflected here, and now we can see into this distal radio-ulnar joint here. The articular disc attaches to the medial ulnar notch of the radius. So we can see it’s attaching here. And then it runs over and attaches the styloid process of the ulna. And this enables this L-shaped joint cavity to be formed, this L-shaped joint cavity to be formed. The ligaments, anterior and posterior ligaments, support the distal radio-ulnar joint and they strengthen the joint capsule.

02:28 So we have ligaments from both the anterior side and the posterior side running over here and then running underneath here. And this help to support the joint capsule. Like the proximal radio-ulnar joint, the distal radio-ulnar joint is involved in pronation and supination.