We see here that the origins and insertions of different muscles are given, and we want to know what type of movement or movements would be created when these muscles contract. So our first muscle here is a muscle of the abdomen, that's the rectus abdominis, and it says that the origin is on the pubis. So I'm going to go ahead and write an 'o' down by the pubis here, and the insertion is on the xiphoid process, that lowest part of the sternum, so I'm going to put an 'I' up there. And remember, our movement, we move the insertion towards the origin. So we're going to move it this way. So if I try and do that, if I try and move my xiphoid process closer to my pubis, I'm going to bend over forward. The more technical way to say that is that I'm going to say that I would flex the spine. Flexion of the spine or to flex the spine, that would be the movement of the rectus abdominis. Alright.
Our next example: this is the sternocleidomastoid muscle here. This is the muscle that sort of wraps around the front of your neck that you can kind of grab onto. And it says that my origin of this muscle is at the manubrium. That's that sort of top part of the sternum there, so I'll put an 'o' there. It also has an origin on the clavicle, but that's right next to it, so it doesn't really change anything. The insertion is going to be on the mastoid process. That's right here. That's that sort of bump right behind your ear there. Well, we're going to try and get this insertion closer to the origin for the movement. Well, if I just worry about my right one here, if I try and get my mastoid process closer to my sternum, I've got to go. So I kind of did two movements there. I rotated my head and I flexed my net. So I'm going to say rotate head, and flex. Alright.
Our third muscle here, we have the adductor longus muscle. Adductor longus has this origin. The origin is on the pubis, so I'll write an 'o' up here. And the insertion is going to be on the linea aspera of the femur. That's that line sort of going down the back of the femur. So if you try and move the back of your femur closer to your pubis, you'd be sort of pulling the leg in. Pulling the leg in towards the midline of the body. You would say that you are adducting or you'd say this muscle adducts the thigh. Alright. Again, understanding the origin and the insertion can tell you the movement of a muscle. And if you understand the movement of a muscle, you should be able to figure out at least pretty close to where those origin and insertions are. More practice problems to follow. Give them a try.