 Okay, now we get to look at all the movements that are possible at synovial joints. If you think about it, synovial joints are diarthrosis. All our other structural categories of joints, those are not diarthrosis, so there's minimal to no movement at those joints. Why bother classifying the movement? Because there's hardly any that's there. Makes perfect sense to me. So, there are very specific definitions of movement when you're talking about an anatomical body. And think about this for a second. We just learned all the bones. We learned all the bony bumps. We learned all these classifications for joints. Next time, we're going to start talking about muscle. When we're talking about muscle, muscle is a new kind of tissue that we haven't looked at a lot. The fact is, muscle shortens. It's a contractile tissue. It starts out this size and then it contracts and it gets shorter. And when a muscle spans a joint by attaching to two bony bumps, you can actually get movement at that joint. We're going to look at what those movements are, what movements are possible at the different joints. And then you're going to visualize where we even talk about muscles. You're going to visualize what is the muscle that we could put, surround, that we could use at that joint as a little machine to make the movement happen. And then when we get to muscles in just like two days, we're actually going to be able to easily look at the muscle and imagine it shortening and be able to describe the movement that's going to happen as a result of the muscle action at that joint. What? Truly. I'm telling you that to say, your study of muscles will be a million times easier if you take this study of movements seriously and commit yourself to learning them all. Are you ready? Let's do it. Our first set of movements, flexion and extension. Most of our movements are described in pairs. Most of the time, we imagine, unless we're told something different, we imagine a body in standard anatomical position and then we imagine a muscle acting on a joint to cause flexion. And in order to, if flexion happens, which we'll talk about in a second what it is, if flexion happens, then some other action must happen to put the body part back where it was and that's usually the opposite. So the opposite of flexion is extension. Now look, flexion is a movement that actually causes the decreasing of an angle in the coronal, no, in the sagittal plane. Let me visualize that for a second. Here's the sagittal plane and if a movement can happen in that sagittal plane, that movement is considered flexion or extension. Flexion is when the angle decreases. Look, starting in standard anatomical position like this, here's my angle, it's like, what is that, 180 degree angle, a straight leg. And then the angle decreases because flexion happened. Flexion of the leg at the knee joint. Let's write that down. Flexion of the leg, what joint? The knee joint. Can you visualize that? All of our movements, we're going to define where they're taking place. If we flexed our leg at the knee joint and we want to go back to where we started, we are going to extend the leg. We're going to go this direction. We're going to increase that angle. We're going to extend the leg at the knee joint. You can also flex, probably the best way to remember is to imagine flexing your forearm at the elbow joint. That's a good one because you can imagine, you know, flexing your bicep, we will learn that, no, we're not actually flexing all of our muscles. We're actually contracting our muscles. So I will contract my biceps in order to flex my arm at the elbow joint. That's flexion, my angle decreased and in that sagittal plane. If I want to put it back, I'm going to extend my forearm at the elbow joint. And it's another muscle. It's not biceps that is responsible for that flexion. It's triceps that's responsible for the extension, putting it back where it started. This is a tricky one. Look at the shoulder. He starts in standard anatomical position. He shortens, he decreases the angle. What? Really? Look, it started out at 180 degrees and now it's not, it's less. And so reaching out in front of you is actually flexing your arm at the shoulder joint. What? True story. Which means extending your humerus at the shoulder joint is returning your arm to that standard anatomical position. I think that's kind of counterintuitive. You can't really hyper-extend it if you think about it. You can't really hyper-flex something, but you can hyper-extend it. You can hyper-extend your knee, return it back to standard anatomical position. You extend your leg at the knee joint. But you could go beyond that. It doesn't feel good, but you could. Your fingers, you can flex your fingers. You can flex your finger at the phalange metocarpal joint. You can extend your finger. I can't like, over-flex. Can you over-flex? I mean, I kind of feel like maybe I could over-flex there. But I feel like, you know, actually I feel like I totally could over-flex. So I don't know why they would call that hyper-flexion. But extension, I could actually extend beyond, beyond standard anatomical position. And that's considered hyper-extension. Your head, I flex, I extend, I hyper-extend. Don't look up my nose. Abeduction, abeduction, and a deduction. We were in the sagittal plane. We are now going to the coronal plane. And abeduction and adeduction are actions that happen in the coronal plane. You don't actually pronounce them abeduction and adeduction. That is a windy-ism because abeduction and adeduction sound really similar to me. So I have to, it's a way for me to think about what I'm saying. Abeduct, abduct. If I abduct my arm, I'm going to move my arm away from the midline. If I adduct my arm, I'm going to move it back toward the midline. You can abeduct and adeduct your fingers. A-D-A-B-duct, I'm abducting my fingers. A-D-duct, I'm adducting them, putting them back toward the midline. You can abeduct and adeduct your legs. You can abeduct and adeduct your wrist. Your hand at your wrist joint. That's cool. The visual of that, look. Here's abeduction away, adeduction toward. All right, you ready for this one? You know you are. Circumduction, what? Circumduction is flexion, extension, adeduction, and abeduction all at the same time. All at the same time, no, like some combination. And one of my students, a rock star, tipped in, hooked up a total, like mathematical explanation of circumduction. And what point we had abeduction, adeduction, extension, and flexion happening. And it was like, whoa, that was really cool. If you combine all of those things, you can get a circular motion that if you want to break it down, break it down, go ahead. What's that going to do? Medial and lateral rotation. We're in a new category, you guys. We, if we're rotating at a joint, we're actually twisting. And look at how great you can see me twisting. I love it. Look, here's my rotation. Oh, perfect. We can rotate like this. That makes you see that it's not, this movement is actually, oh gosh, what is that? That's flexing. Dang it. Why do I use that as my example? Who cares? This, I mean, doesn't that kind of make you think of and moving off to the side? But this is rotation. And you can actually rotate at your hip joints and your shoulder joints. So I can do a medial or lateral rotation at my hip joint and I can do a medial or lateral rotation at my shoulder joint. This is showing you medial and lateral rotation at the hip and I don't see any place where he's showing you medial or lateral rotation at the shoulder, but you can visualize that. Your textbook has nice images as well. All right. Okay, so we had our medial and lateral rotation, which you can visualize and this is just plain old, straight up stone cold rotation. And I want to say that this would be something else that we'll describe in a second. All right. If you rotate your forearm at the joint between your radius and your ulna, that's called pronation and supination. Supination ends up palms forward, standard anatomical position. Pronation ends up palms facing backwards, not in standard anatomical position. You can remember that however you would like to. I remember that if my hands are supinated, I can hold soup in them and eat. If they are pronated, no soup for me. Pronation and supination, although there is some argument that they take place in your feet, oh, holy heck, I can't even visualize that, no. They take place, pronation and supination is only happening in your forearm. Are you good with that? I hope so because it makes me want to cry to think of trying to describe it in your feet. Depression, elevation. That's really straightforward. That's actually a movement that's happening at my scapula. My scapula is elevating and depressing. My mandible, the press, easy, ready. We have a couple of foot words. These are your feet. Take a deep breath. Doorsy flexion. Doorsy flexion is basically lifting your foot, your toes to the sky so that you are walking on your heels. That's doorsy flexing. So I think it's called the duck walk. Duck walk. I'm just helping you remember. Plantar flexion means you're planting your toes into the ground and you're standing on your tiptoes. Think of planting in the ground and I don't know why that makes me go up on my tiptoes. And then doorsy flexion, I'm like flexing. I don't even know. I can't even explain to you where do these words come from. Why? But it's true because everything I say is true. That was your foot. That's standing. That's duck walking and standing on your tiptoes. I seriously think we should do jazzer size with anatomical movement terms. Wouldn't that be a fun game? Yes. Inversion and eversion of your feet. You're not inverting or everting anything else. This would be a great, like, sort the terms, put them into two groups because inversion, eversion, doorsy flexion, and plantar flexion all happen only at your feet. So inversion means you're, what is that? How do you describe that? You're putting the bottoms of your feet together. That's inversion. Eversion is putting the bottoms of your feet away from each other. Inversion, eversion, normal noversion, standing on your tiptoes. That's what this is representing. That is plantar flexion, standing on your heels, doorsy flexion, do it because it's fun. Protraction, retraction, protraction, retraction, protraction, retraction. Opposition is only at that saddle joint in your thumb where your thumb metacarpal connects to the carpal in your wrist. And opposition is this movement. So it's your thumb specifically. It only happens in your thumb. It goes over like this. This is reposition. Opposition, reposition. Opposition, reposition. Nice. And then we have lateral flexion. I think this is lateral flexion. That's why it has its own name. I'm not sure, but it's also of the torso. So lateral flexion is what, it's taking place in the coronal plane. And it's only happening at the vertebrae. That works, because this is at the vertebrae. These are at cervical vertebra. And this is at lumbar vertebra. Okay, that works. So that's lateral flexion. That was that whole thing that confused me back. Are you ready to do jazzercising class? I bet you are. And you probably think I'm joking, but I'm not. We probably will do it.