0:05 Alright deltoids, we have three deltoids. We have upper, upper how many 0:24 guys have an upper deltoid? Yeah I didn't think so, freak, what are you doing 0:31 with an upper deltoid. All right anterior, one of my big pet peeves middle 0:42 not medial, you don't have a medial deltoid, that's a mistake I see actually 0:48 in text books all the time, medial deltoid yes that makes a lot of sense 0:52 for the most lateral structure on your torso. Alright anterior, middle 0:56 and posterior. These are kind of tricky, your anterior delt goes from, where 1:10 was slim, let me get slim. 1:19 You guys know slim? 1:45 I don't know why you guys buy the real bone skeletons, they are so fragile, 1:54 they're super expensive too. You figure after all the years that people have 2:09 been using skeletons they'd come up with something a little bit more durable. Yeah 2:19 all right this is slim, in case any of you wonder why I started working out to 2:26 begin with this is what I looked like in high school. I had the body of a model 2:34 when I started high school, a female runway, model it was terrible, no joke I 2:40 started 6'1, 145 pounds, my freshman year. Not okay, they tried to duct-tape me 2:48 to a pole and I started lifting weights, that's that's the story of how I became 2:53 a personal trainer. All right so this is slim, your anterior delt goes from this 3:02 right here the edge of your clavicle right, your acromion shelf wraps around 3:08 the front into something called your deltoid tuberosity, deltoid tuberosity 3:13 what's a tuberosity? A bone bump, and this is the bone bump that your deltoid 3:22 connects into. You guys can all find your deltoid tuberosity, just take your hand 3:25 palpate your shoulder right, palpate your deltoid, bring it down to the point right 3:30 here, there's your deltoid tuberosity. Not bad right, there you go. So this one kind 3:36 of goes and wraps around like this, so what joint does it cross? 3:43 Your glenohumeral, your shoulder joint. So all of these are going to be shoulder 3:48 joint actions right. So I'm just going to write shoulder up here, that means 3:55 technically we need a new word bank right, we can't use our scapular 4:01 actions for our shoulder. What's my word bank for my shoulder? So I got abduction 4:11 and adduction, 4:20 I got flexion, I got extension, internal rotation, 4:38 external rotation and horizontal AD and AB duction. So if I'm talking about the 5:03 shoulder it has to be one of those joint actions yes. Alright so let's go back 5:08 to the anterior delt, it's this way. So if it runs in front of my shoulder joint, 5:16 what joint action do you think it's going to contribute to? Flexion, good. 5:32 What if I do this, now where is it? Still in front of my shoulder right, but now 5:42 when it shortens how is it going to pull my arm? Horizontally, you guys got that. 5:57 Yeah so that's horizontal adduction. It also kind of wraps around my humerus too 6:14 right, wraps around just a little bit. Generally things that wrap around bones 6:19 or have an obliquity, obliquity is a diagonal to them, will contribute to some 6:27 sort of rotation. Which type of rotation do you think my anterior delt is going 6:33 to contribute to? Internal. 6:45 What do you guys think? Does that make sense? Touch your anterior 6:51 delt for me, all right now internally rotate, you feel that guy contracting a 6:57 little bit? Yeah. Alright so let's look at the middle delt, the middle delt is 7:03 the part of your deltoid that goes from acromion shelf and runs straight down the 7:09 side the deltoid process. So it runs up and down on the side of my body. What 7:17 plane did we say those muscles would probably work really well for? Up and 7:22 down on the side of my body, frontal plane right. So now we could take our 7:28 word bank and chop it down to just our frontal plane joint actions. Alright 7:34 you guys are 50/50, which joint action is this one going to cause when 7:40 it shortens? Yeah this is abducting away. 8:01 Posterior delt, so my posterior deltoid runs from the lateral aspect of the 8:08 spine of my scapula back down to deltoid process, and so now it runs up and down 8:14 on the back of my shoulder joint, what do you think it's going to contribute to? 8:22 Extension sure. What else, what if I did this, if I did this what is this exercise 8:41 called? A reverse or rear delt fly right, you guys have heard that before. So what 8:50 joint action is that? Horizontal AD or a AB? AB, horizontal abduction, and 9:05 what's this, this one's kind of got the wrap around thing happening right. Yeah so 9:12 since this one's back here though, if it shortens it's going to pull me into... 9:18 external rotation; and if you guys caught on, anterior and posterior delt what's 9:31 interesting about them? They're opposites right, anterior flexion, posterior 9:38 extension, anterior horizontal adduction, posterior horizontal abduction, 9:46 anterior internal rotator, posterior external rotator. Cool huh? Fun with anatomy.
