Hey everybody, welcome to Professor Long's lectures in anatomy and physiology. I'm Professor Bob Long. Again, if you've been following these videos, you know they're intended for use by students who are enrolled in my class.
If you're in my class, please follow along in the note set, learn what I teach. If you are not enrolled in my class and you find them helpful, please hit like and or subscribe. That lets me know if I need to keep doing these videos.
We're in the pandemic shutdown, so I'm doing these rather quickly and rapidly. One take videos with my cell phone. If I get enough feedback that's positive, I will do an actual more professional set of videos for you guys.
Now if you're not in my class make sure you learn everything your instructors want you to know but I hope this helps you understand that material. I tend to break things down in a little bit more simpler terms. Now we've been covering joints or articulations.
We're about to do our very last lecture on articulations and we're going to be covering if you're in my class page 49 of my note set we're going to do this table of the types of joint movement. And I'm going to give you either a description and an example of a joint that does that, and you need to know this. So, the first one that is on the list for joint motions is called circumduction. That means to conduct yourself in a circle.
And what's important about this is this is both angular and rotational motions at the same time. Okay, and that movement means that you are rotating at angles or like you're drawing a coin, cone I should say. If I could straighten out my elbow like or my arm like this I could still make big circles.
It's almost like doing windmills or circles with your shoulders. That's called circumduction. There's two joints that we do that really well with. The shoulder. and the hip.
You could lock your knee and you could make your feet go in big circles. We can also do it with our fingers. They're capable of circumduction, particularly certain fingers, but these two are the big ones that do circumduction. So know the description of the motion, know an example of a joint that does it.
The next three are somewhat related. There's, I'm going to try to go in the order. The first one is flexion. To flex a joint means you decrease the angle between joints or between bones.
Okay, so if I were to look at the elbow, I actually have my elbow that can sit at a 90 degree angle. Or if I straighten it out, I can have my elbow at almost a full 180 degrees. I can go to 90 or less than 90, somewhere around 30 degrees or so.
So if I'm decreasing the angle from 180 to less, that is called flexion. Okay? So it's simply the decreasing of the angle between bones. We can flex. Some good examples of joints that can flex would be your elbow, your fingers.
your knee, your toes, but also your hip, your spine, your wrists, your ankles. So I can flex my fingers, I can flex my wrist, I can flex my elbow. And if I start to ball up in the fetal position, I would be flexing my ankles, I would be flexing my knees, I would be flexing my hip.
by decreasing this angle. Okay, the opposite of that is extension. Extension means to increase the angle between bones.
So any joint that I can flex, I can also extend. If I extend my fingers and my wrists and my elbows they're straight. If I flex my spine I would be bending at the waist. If I extend my spine I'm standing straight up in correct anatomical position.
Same thing with my knee and my hip I flex or extend. So when I'm flexing my joints I'm all balled up in fetal position, think fetal flexion, or I can extend and stand upright in correct anatomical position. Now there's one that's related to extending.
called hyperextension. Hyperextension is when we increase the angle between bones beyond anatomical position. So extension is when you increase the angle between bones to anatomical position. If you go beyond anatomical position, that's called hyperextension. So that would be like bending your fingers backwards.
And correct anatomical position might... My neck is extended. If I look up at the ceiling, that's called hyperextension. If I bend my chest backwards, or if my knee joint could hyperextend, or my elbow, I can't do that, but if my elbow went the opposite direction, then that would be called hyperextension, beyond anatomical position, increasing the angle between the bones beyond anatomical position.
A lot of the same joints that can do flexion, do extension, and could possibly do hyperextension. Now, the next one on the list is medial, no, sorry. abduction and adduction. So now listen, if I got my back to you and I'm talking to this wall and I say abduction and adduction, a lot of times it's really, really hard to hear what I'm saying. And if you're sitting behind an orthopedic surgeon and he's telling you to take notes while he's saying, I got abduction and 90 degrees and adduction and this, or a physical therapist and you're taking notes, you can't hear.
So a lot of times... They will say abduction for abduction. Abduction and abduction. To add means to put things together. So in abduction, we move towards...
The midline is the movement of a joint towards the midline of the body. A-B-D-duction, abduction, with a B in it. To abduct means to move away, like when someone's kidnapped, they're abducted. So abduction means to move a joint. Away from the midline or where the bones of the joint move away from midline.
Okay, I know this isn't quite proper English, so you can look up the technical definition. But look, if I'm standing in correct anatomical position, my shoulders and my fingers are... adducted with two D's. Adduction means to move this way.
If I move away from the midline, I'm ABDduction, abduction. If I spread my fingers, that would be abduction. I can do the same thing with the legs. You can abduct or you can adduct and put your feet together.
Okay, so adduction is together. ABD-duction or abduction would be a way like doing jumping jacks. Okay? Now the next two are medial and lateral rotation.
Now these actually have a caveat or a detail about them that's important. So medial rotation means to rotate towards the midline. It's that simple. And lateral rotation is the exact opposite. It means to rotate away from the midline of the body.
And two particular joints that can do this would be your shoulder and the hip. So if I lock my elbow straight, so I'm not going to be doing this, but I'm actually going to rotate my shoulders to where I can actually rotate the humerus in and out. rotating like this, but at the humerus or at my hip. If I lock my knee and my ankle straight, I can still, at my hips, point my toes together or put my heels together and point my toes out.
That would be medial rotation or lateral rotation at the hip and shoulder, okay? Now, I'm going to skip the next two for a second, and I'm going to do inversion and eversion, because inversion is the almost exact same definition as medial rotation. To invert means to rotate towards the midline and to evert eversion means to rotate away from midline. So technically I could say that inversion is almost the same as medial rotation and eversion is almost the same as lateral rotation but they involve different joints okay this would be at the knee or ankle The knees don't move a whole lot, but if I were sitting on a table and I have my knee bent so my hip is taken out of the equation, I can still point my toes inward towards each other at the ankle. And the knee gets a little bit of rotation, but it's mostly at the ankle.
And I can point my toes outward at the ankle. Not talking about the hip movement, I can also... Do it even further, I can medial rotate the hips and invert my toes and almost point my toes at each other. And you can really open up your feet and you would be doing some lateral rotation at the knees.
We'll be doing eversion at the ankle. Okay. I'm sorry.
Lateral rotation at the hip. Eversion at the ankle. Got it?
So the next two, and I skipped these, are pronation and supination. These two are a big deal. So you know we like to ask these ones especially a whole lot. So pronation and to pronate and supination or to supinate and I think there's only one P in supination to supinate or supination are the exact opposites okay so pronation means to rotate the forearm so your palms the palms of your hands are facing Down or backwards. Supination is to rotate the forearm so the palms are facing up or forward.
So, if I have my elbows bent and my palms are facing the ceiling, they're faced up, then I'm in supination. If you can carry a bowl of soup, you're in supination. Now watch, I can pivot my forearms and go into pronation. So my palms are facing down. Now look, if I'm in supination, my palms are forward.
If I'm in pronation, my palms would be facing backwards. So it's just a rotation of your forearm or pivoting of the forearm so the palms are up or forward. or down and backwards.
If you can carry a bowl of soup, you're in supination. If you spill it all the time, you're accident prone, you're in pronation. I hope that helps you remember it.
Now there's a couple more and then we're going to be done and we'll be ready for a lecture test, at least for my classes. Dorsey flexion and plantar flexion. Actually, I think I skipped.
Opposition. No, I did not. Dorsiflexion.
The dorsum of your foot is the sole of your foot. I'm sorry. No, it's not true. The plantar surface of your foot is the sole of your foot, where you plant your feet on the ground. So if I were looking at my feet like this.
and I point my toes down that would be called plantar flexion. If I point my toes up at the ceiling that would be called dorsiflexion. So plantar flexion and dorsiflexion. Plantarflexion would be pointing your toes down like if you're walking on your tiptoes like a ballerina and dorsiflexion would be like if you're walking only on your heels.
You kind of look like a dork doing that so I think of it that way. Opposition. To oppose means the opposite of or to move in the opposite direction.
So I'm just going to describe this one you can write it down. Our thumbs are opposable. That's what makes us primates.
And what that means is I can move my thumb across the palm of my hand. Or I can touch my palm to the base of the pinky. That's called opposition.
Movement of the thumb across the palm of the hand. It allows us to grab things. And then the last ones are going to be protraction and retraction. And then elevation and depression.
Protraction means to move or slide a joint in the forward or anterior direction. Protraction means to slide a joint in the anterior direction. Retraction means to slide a joint in the posterior direction. So retraction, slide backwards or in posterior. Protraction is slide forward in front.
And we can do this at the shoulders, and we can do this at the mandible. So if I stand sideways, I can actually slide my shoulders forward or pull my scapulae back together, and I can slide my shoulders forward and back. That's protraction and retraction.
I can also do it with the mandible. If I bite my upper lip, I am protracting my mandible. If I bite my lower lip, I am retracting the mandible. It can slide or glide there.
Okay? And then... Elevation and depression involve the exact same two joints. Elevation would be to slide your scapulae or your shoulders up. And depression would be like if you reach towards the floor, like in yoga they say try to grab the floor.
Well, that would be depression. Elevation means to move a joint in the upward direction. And depression means to slide a joint in the inferior direction.
So we can also do it with our mandible. If I have my teeth closed and clench my teeth. I am elevating my jaw.
If I depress the mandible or jaw, I'm opening my mouth. So elevation, depression. Okay, listen, that's all the joint movements.
You should know examples of them, know the verbal description of them, fill them in your notes, and do it till you can't stand it, do it till you understand it, do it till you can teach it to someone else, and you'll make an A on your tests. Okay? remember you don't have to be the biggest, the fastest, the strongest, or the smartest person out there. You have to be willing to outwork everybody else. So go outwork everybody and make the highest grade on your next exam.
I hope you had as much fun as I did. I'll see you in the next video. Thanks for watching.