Hi everyone, welcome to Bodyworks Prime. Today we're going over the origin, insertion and action of the pronator quadratus muscle. [Music] Here you can see the pronator quadratus from an anterior view. So this would be the palm of the hand here, and it's essentially connecting the ulna to the radius. The fibers of this muscle run parallel between the two bones, so its contraction is going to pull these two bones towards each other. The pronator quadratus is the deepest muscle the anterior forearm. So it's unable to be palpated or observed superficially. So put simply, what that means is that if we put all of the muscles of the forearm and the hand, and everything back here onto this picture, we wouldn't be able to see the pronator quadrats anymore, because they'd all be covering it up. So now you can see the origin point marked in red on the ulna. This portion of the ulna here, the top portion of it, towards the humerus, that would be the proximal portion of the ulna, and then the part of the ulna, towards the hand here that would be the distal part of the ulna. So if we wanted to describe where this origin point is, we could say it's on the distal and anterior surface of the ulna. Now you can see the insertion point marked in blue and that's going to be on this bone here, which is a radius, and again it's going to be on the distal portion, so if we're going to describe where it's inserting, it would be the distal and anterior surface of the radius. So let's take a look at the actions next. So the actions of the pronator quadratus are in its name, 'pronator' 'quadratus' so we know it pronates, so at the moment I've got my hands and my forearm in a supinated position, so supination would be facing upwards like this, and pronation would be as we rotate over so that they're facing downwards. Another thing to bear in mind with this is that the radius right here is pointing towards the camera at the moment, as it turns over, the radius is actually pointing away from the camera now, and I'll put a little picture up somewhere on the screen here just to demonstrate how that orientation of the radius changes during pronation of the forearm. So if you found this video helpful, or you've enjoyed it, you know which buttons to press, press that like, subscribe, let me know what you thought of the video in the comment, it really helps out the channel. Thanks again for watching everyone. I'll see you all next time.