Alright so the next thing we're going to
start breaking down is the movement
systems of the human body. So the body's fairly complicated right, there's many
different systems that work together to keep us in motion, we're going to start
with the skeletal system. Skeletal system is comprised of what? Bones and joints,
and the definition of a joint is what? Where two bones meet, that's it that's it.
Now I want to mention this because i think the names of joints intimidate
students alright. So the naming of joints, usually the naming of joints is the
combination of the two bones or the two bony prominences, we just squish
the word together. I actually looked it up it's called a portmanteau in English.
I hope I'm pronouncing that right but it's where you squish a word together.
The last time we taught this class there's actually a video where somebody
goes like Kimye right, like that whole relationship um yeah like Kimye. So you
take certain joints like your tibia and your femur right, that's a joint that's
where two bones meet that's commonly referred to as your? It's your tibia
femoral joint or your knee. Your shoulder, what's the technical name for your
shoulder? Glenohumeral what are those two words? The glenoid fossa which is the
socket right inside the scapula, and the humerus, does that make sense? Don't ever
let joint words intimidate you, I guarantee if you just stare at them for
a second, try to splice them in half, you'll start to see where the connection
is. Now rules of the skeletal system -will join us or two bones meet, where any two
bones meet there's a joint. That includes the suture joints of your head right,
just because they don't move it's still where two bones meet, it's a joint. Where
your clavicle meets your sternum, joint. All movement is the result of joint
motion. So you don't have motion outside of
joints, you don't have muscle motion. You have joint motion that's caused by what? Often
muscles contracting, does that make sense. All movement happens at a joint, muscles
pull on bones which result in joint motion. Now maybe one more rule we should
add to this and I'll have to go back and fix this slide is, the type of joint
dictates what motion is allowed at that joint, you guys with me there. Now I'm not
going to get into a huge lecture on the different joint types and all the
technical names, we're just going to go over the different types of synovial
joints real quick, because that will help us and our understanding a functional
anatomy for the rest of the day. So types of synovial joints. Most of these you
probably already heard of; ball and socket, hinge, pivot, gliding, saddle
condyloid, that's it. Now those joints are named after what, anybody know? They're
actually stole, we stole these terms from probably something like carpentry right.
This is the type of joints they make mechanically. For example a hinge joint,
that looks a lot like what? Looks a lot like the elbow right, this is what
they're using in construction of something there. So hinge joints, what are
some examples of hinge joints other than the elbow? Elbow, knee, you guys got
another one? Ankle ankle, yeah you got all this stuff too alright what we're going
to talk about today, ankle, knee, elbow. Important, what type of joint motions
does a hinge joint allow?
Flexion and extension. So when we get to the muscles that cross the elbow, the knee,
the ankle, on the ankle has a couple special joint actions, but at least the
elbow and the knee, are you going to yell out, oh yeah that muscle does adduction?
No your choices are flexion or extension, you got a 50-50 for this muscle. So what
we're going to do with a lot of these guys, is we're going to create word banks.
If I'm looking at a ball and socket joint, what are my ball-and-socket joints?
Hip and shoulder, what will a ball and socket joint allow? Yeah it allows all
those joint actions we've gone over. So let's go ahead and name them. Sagittal,
frontal, and transverse plane joint actions; but the joint actions themselves
are flexion, extension, abduction, adduction, internal, external rotation,
horizontal abduction, horizontal adduction. Alright so when we get to ball
and socket joints we got a few more choices. Pivot joints, yeah so yeah, you
got C1 and C2 which we're not going to talk about the muscles of the neck today,
but you guys already know that this is rotation right. Where else do you think
you might have a pivot joint based on that rotational ability? Yes yes say it a
little louder, your radius and ulna alright. So your proximal radioulnar joint
is a pivot joint. Now we call rotation here something different, What do we call
this? Supination you hold a bowl of soup, pronation, you Pro it out. You're not
gonna say it are you, you're like I'll flip it over.
Sorry you don't have to be as corny as I am. Alright plne joints, plane
joints are gliding joints. What do you think just based on that
little picture right, what do you think they would be capable of doing? It's more
like a lot of little motions in a lot of different directions, but not very far
right. Right so you could rotate this way, you can slide this way, you can slide
this way. Can anybody think of of some joints that might move like that? So some
of your carpal bones, yes right also some of the bones in your ankle, and then
here's something that we are going to talk about quite a bit, we're not going
to talk about wrist muscles very much, but where else do we have gliding joints?
Not scapula, the spine. So interesting guys, like if you look at the
spine you guys think you have a lot of motion at the spine right, but it's yeah
it's the combination of all of these, look can you guys see these little tiny
joints right, these are the facet joints; all right all these little joints are
moving like this in all those different directions we can move the spine, a
little bit ,that kind of makes sense. You really if you think about it, you can't
move any one segment very much. If I were to come and like brace your rib cage
and said, so that you couldn't move below your rib cage, and said go ahead rotate
at your thoracic spine, you wouldn't get too far.
Now we have saddle joints, and I went ahead and wrote in the examples this one,
your first CMC in your thumb, and your sternoclavicular joints are saddle
joints; but based on that picture, how many how much motion do you think you're
going to get out? How many planes? Two right, it's just like this just like
being on the saddle of a horse, you can kind of go forward and back right, and
you can go over. Anybody who's been on a horse knows that you can go over right, so
we're all scared of. What can't you do if you're sitting on a saddle? You can't
can't do anything horizontal, you can't twist. And then there's condyloid joints,
like I said, this is one of those things we're not going to go over much today.
Where your carpals meet your radius is sometimes called a condyloid, they have
it like a ellipsoid shape to them, with a little bit of a divot, they allow a
couple planes of motion really really well, and maybe some freedom outside of
that. The knee sometimes it's called an ellipsoid joint as well. When we get into
some more technical stuff tomorrow as far as function, and posture, and
analyzing function, we'l see that the knee is not a perfect hinge right. It
doesn't do just flexion and extension. What else can you need to a little bit
of, do you guys know? It does a little bit of rotation. So why am i teaching you guys
this stuff? As far as I'm concerned everything you guys are going to learn
from me is for practical reasons. I'm real big on practical education, so I
kind of mentioned this before, I'm going to ask you what the joint type is,
because the joint type is going to dictate what? The motion allowed at that
joint. So when we talk about the muscles that move that joint, what are your
options going to be for joint actions?
So you have joint, joint type, joint type dictates the amount of the actions that
are available. So when we talk about muscles, what are your choices going to
be? This is an easy question guys, I'm not trying to trick you. The same joint
actions that were available at that joint. In other words if I'm talking
about the elbow, we already talked about the elbow is a hinge joint right, which
means what's available to me? Flexion and extension, which means if I'm talking
about the biceps, the biceps that crosses the elbow is either going to do flexion
or extension. In this case it's in front of the joint, so you expect it to do
flexion, does that kind of makes sense. So it's just going to help us narrow in,
like I said the point of this class is to get conceptual with our functional
Anatomy knowledge, I'm not trying to teach you how to memorize.