0:05 So let's talk about joints of the shoulder girdle. We just learned all 0:09 these joint actions and now I'm going to throw a little wrench in our joint 0:14 actions chart, but joint actions of the shoulder girdle are acromioclavicular joint 0:20 and our sternoclavicular joint. Now those sound 0:24 like really huge, technical words, well remember when I was talking about 0:28 anatomy being another language, those aren't huge technical words, they're 0:32 actually referring to two specific bones or two specific points with on a bone. 0:38 Your acromioclavicular joint everybody feel this right here, feel that shelf 0:43 where you don't have any de ltoid, it's just above your deltoids, it 0:46 doesn't matter how big your deltoids are you still don't have deltoids here. 0:49 Right here you feel the shelf, well that's part of your scapula called your 0:55 acromion process. What's this bone right here called? This is your 1:01 clavicle, your collarbone it's your clavicle, so where your acromion 1:07 process and your clavicle meet is called your acromioclavicular joint. That's it, 1:17 it's not so bad right. It's like when you try to smash words together, you guys 1:22 ever do that, like you see a cute couple and you like try to smash the girls name 1:26 and the guys name together, you guys ever done that before? Right don't they do 1:30 that with like stars, huh Kimye, awful, terrible. Anyway, but you get what 1:41 I'm saying, that's all they've done here, taking acromion and 1:44 clavicular and said, "You know what'd be really cute? If we call it acromioclavicular." 1:48 That's the name of the joint, for short it's AC joint. Sternoclavicular, what do 1:53 you think sterno is related to? Sternum and the clavicle feel right here, 1:59 do a little of this, you can kind of feel there's a joint right here. 2:03 The funny thing is is your entire shoulder girdle including your 2:07 arm, the only bony attachment to your body is this joint right here. Craziness. 2:13 That's crazy. Alright so that's your sternoclavicular 2:18 joint. Now although those are the two joints of the shoulder girdle, we don't 2:27 usually refer to motion of these joints. In further classes you will, those of you 2:33 guys going back for your ATC, your DPT, master's in kinesiology, you'll start 2:38 looking at these joints specifically, but for the most part those two joints help 2:43 to dictate motion of the scapula, and we refer to motion of the scapula in 2:49 analysis. Most of the muscles that would even impact these joints are actually 2:53 attached to the scapula, does that make sense? So I don't want you guys to think 2:57 that the scapula is a true joint, sometimes it's called the scapulothoracic joint. 3:02 It's not actually a true joint, it's just more convenient to label 3:05 it that way. Now unfortunately you guys just learned all of these joint actions 3:09 right, flexion, extension, abduction, adduction, horizontal abduction, adduction 3:12 external internal rotation, lateral flexion, you learned all that. The 3:16 scapula doesn't use those, so we have to learn a separate set of joint actions. 3:23 You ready? They're actually not that bad. Most of them occur in the frontal 3:30 plane. Does anybody want to take a wild guess why most of them would occur in 3:35 the frontal plane? Think about how I taught you guys the frontal plane. 3:48 The muscle, the way the muscles run, that's part of it. I told you to think about the 3:52 frontal plane as if you had what? A plane of glass in front of you. What's in 4:01 front of the scapula? The ribs. Is there going to be a whole lot of sagittal 4:07 plane motion of the scapula with ribs in front of it? Now that kind of makes sense. 4:11 So our frontal plane joint actions, our scapular joint actions rather 4:34 start with, 4:47 that's my scapula everybody cool with that, all right start with this. If I go 4:53 up it's called elevation, because elevators take you up, I know they can take 5:04 you down too but stay with me. So elevation is up, that makes sense right 5:08 that's not too bad. What do you think the opposite of elevation is? Depression. 5:12 Don't most people who are depressed kind of have their shoulders down anyway. 5:17 Okay so we got elevation, we have depression. 5:29 The next joint actions you kind of have to think of the scapula as a pinwheel. 5:35 You remember pinwheels? They were these little, there was like a stick, 5:43 stick, right then they had these like leafy things, how's my art coming? 5:52 Is it getting better? Better than the horizon, that kind of looks like a 5:58 pinwheel and you'd like blow on it and it would spin, you know what I'm 6:01 talking about? Or am I just totally dating myself at this point. Pinwheel? 6:06 You have to kind of think of it as a pinwheel, it's a type of rotation 6:11 although it's a rotation in the frontal plane this way, known as upward and 6:16 downward rotation. Now to decide which way is up and which way is down we need a 6:22 point of reference, you with me? That point of reference for the scapula is 6:29 your shoulder socket, this part where my humerus hangs down my arm, this is known 6:38 as your glenoid fossa. When your scapula spins so that we end up with 6:57 glenoid fossa pointing upward, which rotation do you think that is? That's 7:03 upward rotation, moving back down is going to be downward rotation. What do 7:12 you think we see these joint actions, anybody want to take a guess? Frontal 7:19 plane motions sure, give me an exercise? Shoulder press would be what? Upward 7:28 rotation, when would I see downward rotation? Pull up, so if 7:34 I'm doing a pull-up, my scapulae are starting to do this, which is that downward 7:38 rotation. Has everybody got that visualized? Alright let's talk about the 7:42 last ones. 7:59 If I drew you from the top, this is your torso this is your head, sorry if any of 8:08 you are offended by this picture I don't mean anything by it, not that big, it's my 8:15 torso. So we got torso head and then we got scapula, it's a great picture isn't 8:28 it. If I do this, all right if I do this thing, so in essence I go from here to 8:39 here, can you see how that would be transverse plane movement? Parallel 8:47 to your table since this is a top-down view. Now the question is what do we call 8:51 that? This is protraction. How many of you have seen this guy in 9:00 the gym, you can now refer to them as Captain Protraction. No? None of you 9:09 are that nerdy? Any of you know what ILS stands for? This is a good one 9:15 too, you don't know ILS? "Imaginary Lat Syndrome." You can throw 9:23 that around amongst yourselves. So protraction, what action, what 9:29 exercise might we see a little protraction in? Benchpress sure, we really 9:34 need protraction to bench pres. In fact, anytime we do pushing motions, we need 9:40 some protraction. What's the opposite of protraction? Retraction, so that's 9:46 when my scapulae actually come closer together and almost touch in the middle. 9:55 We got the green as protraction, when we got red we got retraction. 10:06 Those six joint actions are your big joint actions for the scapula, 10:10 those are the ones you will see most often, you guys cool with that? Now there 10:17 is two other joint actions for the scapula that you don't run into as often 10:22 in your textbooks. Those of you who continue with my courses you're going to 10:27 have to be aware of, which is there is one set of sagittal plane motions for 10:33 the scapula. It's called anterior and posterior tipping. So we won't refer to 10:43 this too much for the rest of the day, you can put a little star by this, 10:47 as bonus material, but if I drew a skeleton from the side, 11:03 all this are my vertebrae, how you like my picture? Good. Scapula sits just 11:17 like this. Now anterior and posterior tipping is sagittal plane motion, which 11:23 means it's in which direction? Forward and back right? So what happens with the 11:31 scapula is it can kind of crawl over the top of the rib cage, and it can tip 11:38 anteriorly. Alright so when we refer to this tipping it's in reference to the 11:45 top of the scapula, and then what would be the opposite of anterior tipping? 11:51 Posterior tipping, exactly. So that would be posterior tipping. When we get into a 12:01 little bit more complex postural dysfunction and correcting postural 12:05 dysfunction and improving mechanics of the the upper body, this becomes 12:10 important. Everybody's got those? Anybody want to take a guess when anterior and 12:18 posterior tipping happens, like some exercises? Shrugs, yeah you don't really 12:27 force it in a shrug. It's probably going to be more like an arm motion that 12:32 anterior and posterior tipping gets included in, anybody want to guess? 12:37 Swimming possibly, when during the swim? So if I do this, what's going to 12:47 happen to my scapulae? They're going to posteriorly, do it, do it, you can feel your 12:54 scapulae push into your rib cage, it flipped this way, so that's 12:58 posterior tipping. Anterior tipping is, yeah if you did one of these 13:03 things, everybody do this, because it looks hot, like Kimye, 13:11 this is anterior tipping. Everybody's got their scapular motions down.
