You can only view 3 videos without an account. Become a Member to access all videos on the website.
Deltoid Muscles: Video #8 of Introduction to Functional Anatomy
The deltoid muscles are located in the shoulder and part of the upper arm areas of the body. They are responsible for shoulder movement, such as abduction and extension, and also shoulder stabilization. The deltoid is composed of three parts: the anterior, lateral, and posterior deltoid, which all originate from the clavicle and acromion and insert onto the humerus. The deltoid is vital for sports that require aggressive movement of the arm and shoulder,
Transcript
00:00:0500:00:24
Alright deltoids, we have three
00:00:0500:00:24
deltoids. We have upper, upper how many
00:00:2400:00:31
guys have an upper deltoid? Yeah I didn't think so, freak, what are you doing
00:00:3100:00:42
with an upper deltoid. All right anterior, one of my big pet peeves middle
00:00:4200:00:48
not medial, you don't have a medial deltoid, that's a mistake I see actually
00:00:4800:00:52
in text books all the time, medial deltoid yes that makes a lot of sense
00:00:5200:00:56
for the most lateral structure on your torso. Alright anterior, middle
00:00:5600:01:10
and posterior. These are kind of tricky, your anterior delt goes from, where
00:01:1000:01:14
was slim, let me get slim.
00:01:1900:01:23
You guys know slim?
00:01:4500:01:54
I don't know why you guys buy the real bone skeletons, they are so fragile,
00:01:5400:02:09
they're super expensive too. You figure after all the years that people have
00:02:0900:02:19
been using skeletons they'd come up with something a little bit more durable. Yeah
00:02:1900:02:26
all right this is slim, in case any of you wonder why I started working out to
00:02:2600:02:34
begin with this is what I looked like in high school. I had the body of a model
00:02:3400:02:40
when I started high school, a female runway, model it was terrible, no joke I
00:02:4000:02:48
started 6'1, 145 pounds, my freshman year. Not okay, they tried to duct-tape me
00:02:4800:02:53
to a pole and I started lifting weights, that's that's the story of how I became
00:02:5300:03:02
a personal trainer. All right so this is slim, your anterior delt goes from this
00:03:0200:03:08
right here the edge of your clavicle right, your acromion shelf wraps around
00:03:0800:03:13
the front into something called your deltoid tuberosity, deltoid tuberosity
00:03:1300:03:22
what's a tuberosity? A bone bump, and this is the bone bump that your deltoid
00:03:2200:03:25
connects into. You guys can all find your deltoid tuberosity, just take your hand
00:03:2500:03:30
palpate your shoulder right, palpate your deltoid, bring it down to the point right
00:03:3000:03:36
here, there's your deltoid tuberosity. Not bad right, there you go. So this one kind
00:03:3600:03:43
of goes and wraps around like this, so what joint does it cross?
00:03:4300:03:48
Your glenohumeral, your shoulder joint. So all of these are going to be shoulder
00:03:4800:03:55
joint actions right. So I'm just going to write shoulder up here, that means
00:03:5500:04:01
technically we need a new word bank right, we can't use our scapular
00:04:0100:04:11
actions for our shoulder. What's my word bank for my shoulder? So I got abduction
00:04:1100:04:13
and adduction,
00:04:2000:04:33
I got flexion, I got extension, internal rotation,
00:04:3800:05:03
external rotation and horizontal AD and AB duction. So if I'm talking about the
00:05:0300:05:08
shoulder it has to be one of those joint actions yes. Alright so let's go back
00:05:0800:05:16
to the anterior delt, it's this way. So if it runs in front of my shoulder joint,
00:05:1600:05:25
what joint action do you think it's going to contribute to? Flexion, good.
00:05:3200:05:42
What if I do this, now where is it? Still in front of my shoulder right, but now
00:05:4200:05:57
when it shortens how is it going to pull my arm? Horizontally, you guys got that.
00:05:5700:06:14
Yeah so that's horizontal adduction. It also kind of wraps around my humerus too
00:06:1400:06:19
right, wraps around just a little bit. Generally things that wrap around bones
00:06:1900:06:27
or have an obliquity, obliquity is a diagonal to them, will contribute to some
00:06:2700:06:33
sort of rotation. Which type of rotation do you think my anterior delt is going
00:06:3300:06:39
to contribute to? Internal.
00:06:4500:06:51
What do you guys think? Does that make sense? Touch your anterior
00:06:5100:06:57
delt for me, all right now internally rotate, you feel that guy contracting a
00:06:5700:07:03
little bit? Yeah. Alright so let's look at the middle delt, the middle delt is
00:07:0300:07:09
the part of your deltoid that goes from acromion shelf and runs straight down the
00:07:0900:07:17
side the deltoid process. So it runs up and down on the side of my body. What
00:07:1700:07:22
plane did we say those muscles would probably work really well for? Up and
00:07:2200:07:28
down on the side of my body, frontal plane right. So now we could take our
00:07:2800:07:34
word bank and chop it down to just our frontal plane joint actions. Alright
00:07:3400:07:40
you guys are 50/50, which joint action is this one going to cause when
00:07:4000:07:48
it shortens? Yeah this is abducting away.
00:08:0100:08:08
Posterior delt, so my posterior deltoid runs from the lateral aspect of the
00:08:0800:08:14
spine of my scapula back down to deltoid process, and so now it runs up and down
00:08:1400:08:21
on the back of my shoulder joint, what do you think it's going to contribute to?
00:08:2200:08:41
Extension sure. What else, what if I did this, if I did this what is this exercise
00:08:4100:08:50
called? A reverse or rear delt fly right, you guys have heard that before. So what
00:08:5000:09:05
joint action is that? Horizontal AD or a AB? AB, horizontal abduction, and
00:09:0500:09:12
what's this, this one's kind of got the wrap around thing happening right. Yeah so
00:09:1200:09:18
since this one's back here though, if it shortens it's going to pull me into...
00:09:1800:09:31
external rotation; and if you guys caught on, anterior and posterior delt what's
00:09:3100:09:38
interesting about them? They're opposites right, anterior flexion, posterior
00:09:3800:09:46
extension, anterior horizontal adduction, posterior horizontal abduction,
Related Videos
Nervous System and Receptors 2: Video #24 of Introduction to Functional Anatomy
Pectoralis Major, Latissimus Dorsi and Teres Major: Video #10 of Introduction to Functional Anatomy
Functional Roles of Muscles: Video #25 of Introduction to Functional Anatomy
Muscles of the Lower Leg: Video #17 of Introduction to Functional Anatomy
Deltoid Muscles: Video #8 of Introduction to Functional Anatomy
Improve Your Public Speaking Repetition
Joints of the Shoulder Girdle and Scapular Joint Actions: Video #6 of Introduction to Functional Anatomy
Anatomy of the Gluteus Maximus (Outtake from Functional Anatomy Workshop)
Basics of the Human Movement Systems: Video #5 of Introduction to Functional Anatomy
Improve Your Public Speaking Setting the Stage