Radius

00:01 So, the radius sits within the lateral aspect of the forearm.

00:04 It's running adjacent to the ulna which we spoke about a moment or two ago.

00:09 It again, has a proximal end that helps to form the elbow joint.

00:12 It has a shaft and here, we have the distal end of the radius.

00:17 If we have a closer look at the radius, we can see we have the head and then, we have the capitulum of the humerus and these are the two aspects that articulate together to help form the elbow joint, along with the humerus and the ulna.

00:30 But due to the shape of the capitulum and the head of the radius, we have a different movement.

00:34 Here, it can rotate allowing pronation and supranation as opposed to flexion and extension.

00:40 Once we add the ulna into position, we can now see how the head of the radius actually articulates on the radial notch of the ulna. And that again, permits the rotation of the head.

00:51 Distal to the head of the radius, we find we have a neck and then, we'll have a tuberosity again, the radial tuberosity, again, an important attachment site for muscles which we'll come onto later on.

01:03 Now, we can see both the anterior and the posterior view of the radius.

01:08 We can see we have an anterior border. And now, we have an interosseous border as well.

01:12 Again, where those interosseous membrane fibers can attach between these two bones.

01:19 We have the posterior border, we have a lateral surface.

01:21 And here, we have the anterior surface and its posterior version.

01:27 If we then move onto the distal end of the radius, we can see again, it has a large head region, and also, the styloid process of the radius. So, here, we have the styloid process of the radius which pushes out just like the ulna had a styloid process as well. And here, we have a large carpal articular surface.

01:46 This helps to articulate with the carpal bones and form the wrist. We'll look at those in a moment or two.

01:52 We can also see here how we have the ulnar notch of the radius and this is important because during pronation and supranation, the head or the distal head of the radius is actually going to overly the distal head of the ulna. So, what we're going to have is rotation occurring during pronation and supranation that's articulated at this joint, allowing the distal end of the radius to move across and then, over onto the ulna.

02:18 And this notch allows this to happen. We also have another important landmark here.

02:24 This is the dorsal tubercle. Some textbooks may call it the Lister's tubercle.

02:28 We'll come back to these tubercles later on when we talk about the various muscle attachments.

02:34 The most prominent location for a fracture in this region is very much the distal radius, a bone that I fractured myself.

02:41 One of the most common types of bony fracture occurs at the distal fracture, usually, when you fall and you break your radius on an outstretched arm which is trying to break your fall.