- Hello, massage nurse.
Today, we're gonna be doing lesson five,
the muscles that move the shoulder.
So there's 11 muscles involved.
I was only able to draw most of them.
I didn't do the biceps or the triceps
'cause he's got very good biceps and triceps,
so you can see those.
And they're part of a future lesson,
so I don't wanna draw them today.
So the movement of the shoulder,
I drew them on separate sides
because it'll show better.
However, they are both of the muscles that I draw.
All the muscles that I drew are on both sides so you have a
deltoid here, you have a deltoid over there.
The deltoid is the most superficial muscle of the shoulder.
And it originates at the half lateral part of the
clavicle and all the way to the back.
It also originates right here on the spine of the scapula.
So this is the spine of the scapula,
the half part of the clavicle.
And it inserts at the deltoid tuberosity of the humerus.
It has three parts, the anterior fibers,
the middle fibers and the posterior fibers.
And you know,
they all are for different functions and I'll show you right
now, but this is the deltoid.
And this is the deltoid tuberosity on the humorous ward
inserts, which is just means that it's a little bit,
in an attachment site.
And then we have over here on this side,
we have the pec major,
which is another one that works the shoulder.
And it originates from the sternum to the,
about the sixth rib.
And then it inserts on the humerus right there and half of
the clavicle.
So these other origins,
remember the origins are more medial to the body.
And then the insertions are more distal.
Cause this is,
you know, this is the more fixed one.
So it's going to bring, help, bring the arm, you know,
it's going to anchor right here and bring the arm over.
So then we move on to the coracobrachialis.
The coracobrachialis is the
muscle that originates at the coracoid process.
If you remember that the coracoid process is part of the
scapula that's on the anterior part of your body.
It's very bony it's that little hook on the scapula.
You already had the scapula on lesson one and you drew
it and that little hook that's the coracoid process right
there.
The coracoid process also has two other attachments there.
Those short head of the biceps and the pec minor insertion.
So it goes from the origin to the insertion,
to the medial shaft of the humerus.
So this is the coracobrachialis , pec major.
We drew part of the pec minor in lesson four.
Cause that moves the scapula.
These are shoulder muscles that move the shoulder.
So then you keep turning and turning here.
Now we have, I drew the SITS muscles.
These are the rotator cuff muscles.
The rotator cuff muscles are the ones that anchor the
shoulder and the glenoid cavity.
The glenoid fossa is,
is where the part of the scapula and the humerus and source.
This is a ball and socket joint.
It is the one with a biggest range of motion.
Thus it's easy to dislocate.
And these muscles here,
keep it in place.
The deltoid is more superficial and on top
like you saw that I drew it on the other shoulder.
The deltoid is the one that's on top.
The supraspinatus is on top of the spine of the scapula.
So it starts on the super superior part of the scapula and
it inserts and the greater tubercle of the humerus.
This is the infraspinatus.
Which originates here on the medial part of the scapula and
also inserts at the greater tubercle of the humerus.
The teres minor is also part of the
four rotator cuff muscles.
It also inserts right here at the greater tubercle of the
humerus and the subscapularis
is the only one that I didn't draw because it's on the
anterior part of the scapula.
So it's sandwiched,
it's sandwiches on the anterior part of the scapular here on
the other side of this here, that's the subscapularis,
that's another one of the four rotator cuff muscles.
So the acronym is SITS.
SITS for supraspinatus, S supraspinatus the S infraspinatus,
the I, T for the teres minor
and then the subscapularis is the other S so they're called
the SITS muscles.
And they're the ones that hold the humerus in place,
you know, they anchor the humer.
So it doesn't dislocate.
So the,
those subscapularis inserts at the anterior part of the arm.
It inserts right here
in the lesser tubercle of the humerus.
And it's usually when people tear a rotator cuff muscle,
it's usually that tendon, cause it is the largest tendon,
the largest tendon of all four of them.
It's the one right here on the anterior
lesser tubercle of the humerus.
And like I said,
that one is anterior to the scapula and it inserts on the
anterior part of the arm where all the other three are in
the posterior.
So that's the one rotator cuff muscles.
Now this is the teres major,
it sits on the lateral part of the scapula.
It originates and it inserts under,
below all the SITS muscles.
So also on the humerus and it's larger,
it's a little bit larger than the teres minor.
Then another muscle that helps with the movements is the
lat, the latissimus dorsi
or dorsi depending on who's pronouncing it,
but latissimus dorsi or dorsi, you know,
originates from like the sixth thoracic vertebrae, you know,
all the way to the lump, you know,
the lumbars and the iliac crest.
So here's the iliac crest.
And so all of this is the origin and then inserts on the,
on the humerus too.
So think of the fibers I've been telling you guys, like,
how do the fibers, you know, how do they move?
How, how are they?
So think of this with this, one's going to pull the arm in,
you know, so think of, think about that.
Start thinking about how are the fibers, you know, located.
So what's going to happen?
What movement are they doing?
So these fibers would pull the arm back up.
So I'm going to tell you right now about flexion and
extension.
Oh,
another thing I want to tell you about the latissimus dorsi
is this muscle makes the posterior axilla,
your axilla fold comes from the, from the,
just the latissimus dorsi.
Now on the anterior part,
the one that makes the anterior axilla is the pec major.
So see this, this part right here of your axilla,
that is your pec major.
So you can go in and work this muscle.
And the pec minor is underneath the pec major.
Remember that originates from ribs three, four, and five,
and then inserts at the coracoid process here.
So this that the pec minor moves the scapula.
So it's not part of the shoulder movement for this one.
So this is the pec major, coracobrachialis, deltoid has
three anterior, middle and posterior fibers.
The latissimus dorsi, supraspinatus, infraspinatus, teres,
minor, and teres major, all of those combined,
even though I drew on different sides,
all those 11 muscles combined move the shoulder and the ones
I didn't draw where the triceps,
Show us your triceps and biceps, here are your
triceps.
So these are the triceps, triceps for three origins.
So the triceps here, and then the biceps, you know,
right here also move the, you know, help move the shoulder.
Oh, so let's talk now about the movements.
Okay. Let me see.
You can go enter your,
so when you do fluxion,
fluxion of the shoulder,
your shoulders go forward.
Fluxion this is the pec major.
So it's pulling that arm,
the pec major, the anterior fibers of the deltoid,
the coracobrachialis and the biceps.
All those muscles are doing, helping with flexing.
The shoulders forward extension of the shoulders extension
would be the latissimus dorsi pulling it back.
That teres major, the pectoralis major and the triceps,
the triceps too.
They're helping move the,
the muscles back now for abduction.
That's the supraspinatus and the deltoid actually,
the supraspinatus starts abduction like within the first 15,
the first 15, what do you call it?
A range that day rom comes from the supraspinatus and then
the middle deltoid also abducts away from your body.
So to add it back up the deltoid, I mean the,
the pectoralis major and the teres major and the
latissimus dorsi, they're pulling the arm back down and the
coracobrachialis too pulls down.
And the triceps also help with abduction.
Now for medial rotation, that would be the latissimus dorsi,
the teres major,
the anterior deltoid is pulling the arm and the pec major.
So they're pulling the arm in that's medial rotation.
Lateral rotation would be the infraspinatus the back.
The teres minor.
And the posterior deltoid see that they pull the muscles,
you know, the muscles pull for lateral rotation.
So those are the movements of
the shoulder you've got fluxion and extension, abduction,
adduction, medial rotation, and lateral rotation.
So this is what I want you to do like I said,
I drew nine muscles.
I didn't draw the biceps and the triceps,
and you don't have to for your homework either,
but I do want you to draw the major ones and pick one side
to draw them on.
Like I picked to do the pec on this side and the
coracobrachialis on that side,
the deltoid on this side and on the back, you know,
you can just draw them.
Latissimus dorsi on one side.
And then on the
the major ones that I really want you to learn is the,
the SITS, the rotator cuff muscles.
Remember this is the, the ball and socket joints,
synovial joint with the greatest range of motion anywhere in
the body.
However, is the one that dislocates really easy.
So you're going to see a lot of injuries with rotator cuff
problems, and it's very important for you to work the,
you know, the origins and insertions of the muscles.
And I have a video for treating frozen shoulder.
This is also the muscles that are involved with frozen
shoulder.
So make sure that you learn where your muscles are.
That's gonna be your homework,
and then so draw all the muscles.
And these are lessons five muscles of the shoulder movement.
And thank you Leo again for being our volunteer.
And until the next time guys create a great day.