00:01
So now let's look at the radius, this is the bone
that lies on the lateral aspect of the forearm
and again we've got anterior, posterior and
the medial or an ulnar view which we can see in this
picture here on the slide. The radius is shorter
than the ulna and it's positioned more laterally.
00:24
Proximally we have got some details that I'd
like to talk about. We have got the head of
the radius and that is going to articulate with
the capitulum of the humerus. But importantly
the head also articulates with the radial
notch of the ulna and these two bony features
articulations with the capitulum, articulations
with the radial notch allow a complex arrangement
of movement. So we can see we have flexion
of the wrist joint and we also have the ability
to supinate and pronate, where we turn the
forearm over. The two bones of the forearm
can turn over and that supination and pronation
we'll talk about that later on. But this is allowed
to happen because of the bony features we
can see on the radius. So the head of the
radius here, it is going to articulate
with the capitulum of the humerus and then the
head of the radius also articulates with the
radial notch of the ulna. So we can see the
head here. We can see the head on this posterior
view and also on this medial or the ulna view
of the radius. The shaft, again it has got the sharp
interosseous border, just like the ulnar did, allowing
interosseous membrane to articulate
and the shaft of the radius is going to widen
quite distally. And again we have a radial styloid
process that can be palpated on the lateral
aspect of the radius.
01:53
If you have a few more details looking at
this distal end of the radius, then we can
see we have an ulnar notch. We can see here
in this allows articulation with the head
of the ulna, we can see this clearly on the
medial view which is the ulnar view so we
can see that clearly here. We have got
the ulnar notch allowing articulation with
the head of the ulna. As I have mentioned
we have got the radial styloid process and
we have also got the radial styloid notch
as well, most laterally within the radial.
02:27
We also have what is known as the dorsal tubercle
and this dorsal tubercle is important as it
acts as a pulley for the extensor muscles
of the thumb and we will cover these in more
detail when we look the extensor muscles within
the forearm. And it's important to remember
this dorsal tubercle on this posterior surface
of the radius allowing various muscles to
attach the joint at a slightly different angle.
So here we can see how series of bony landmarks
on the radius.