hi um today um I want to talk about shoulder complex um shoulder complex function um is to place our hand in position so that we can use our hand to do uh U value occupations in our life um but the term shoulder complex well it's really complex so it kind of involve and all structures of the actual and perpendicular skeleton that contribute to uh the upper extremity movement so basically uh the shoulder region uh involve the sternum um the reib cage cical um the scapula and the humorus and all the joints that kind of form by these uh bony structure so uh the primary joints for uh the shoulder complex are um um the first one the sternum cicular joint which is here and uh the acromium on scapula so the acromial clavicular joint which is right here and a gleno humeral joint which is the most famous One um for um what we call shoulder joints but it's really uh the gleno humoral joint right here and then the next one is uh the scap uh scapulo thoracic uh articulation so there's not really uh a joint but it's some kind of like a articulation um surface is is basically the the the whole uh scab moving on uh the thoracic okay so uh when you hear um shoulder uh complex um it typically involve shoulder girdle and the shoulder joint so what's the difference between shoulder girdle and shoulder joint in should shoulder joint is typically uh mean for uh the glenohumeral joint and all other three um joints that we referred it to um shoulder girdle so basically shoulder girdle it involve activities of the scapula the clavicle sternin and the rib and the Sher joints it involv the activities of the scapula and the humoral bone okay so the the joints that included in the shoulder girdle um our sternal um I'm sorry sternal clavicular joint AC chromian clavicular joint um scapulo um I'm sorry scapulo U thoracic joints and of course the shoulder joint is really the glal humoral joint and the movement for shter girdle is typically uh the scapular movement which is elevation ression protraction retraction or scapular abduction for uh for protraction or uh scapula adduction for uh retraction and upward rotation and downward uh rotation and for shoulder movement typically we know uh there are shoulder flection extension abduction um adduction external and internal rotation and of course and then there's a horizontal abduction and adduction okay um in the structure for U the The shter Joint we will talk about that later but um it involve the glenola and the structures including the leum the capsules and the ligaments and uh because it's a a b and socket joint it typically Ty Al uh well it many rely on the ligament and the muscle to keep the uh the the humoral bone within the gleno FASA and that's why it's the most uh mobile joint and it's very easy uh to dislocate The Joint as well so now let's look at uh the shoulder girdle first um looking at the shoulder girl right here uh we first uh want to talk about the sternal clavicular joint um the SC joint so the SC joint is a tri actual um joint yeah the clavical uh well the r of motion for this joint is really really tiny so it's hard to see but it really um is a tri actual joint uh which um um it has movement in all three um plants and look at this so the clavicle uh The Joint the uh the side of the clavicle uh form the joint with the sternum it's like a a convex shape so you kind of go into the um opposite direction when um when uh we have the movement right here um and uh um what what you need to pay attention is the ligaments that Cann of form the the stability of the SC joint so the first one is inter clavicular ligament not going to connect the two clavicle bone and then you need to know uh the sternum and then the clavical um ligament mean uh name a sternal clavicular ligament right here and then it's it's it's connection to the rib so there's a u Costco clavicular ligament right here so these three types of ligament kind of secure the SC joint so that uh the r of motion of this uh clavical bone uh in relation to uh the stern is really really um limited so here is uh the movement of the SC joint so the clavicular um uh elevation when we uh move our shoulder up or down that's the uh depression uh we move our shoulder forward that's U the clavicular protraction and then retraction and of course uh when we do the circle movement um there's a um um um rotation as well so you can kind of see that um SC joint kind of contribute to shoulder movement when when we need to move the shoulder but it's uh but because it's really tiny like typically people put more attention to um the GH joint but the the SCC joint did uh contribute to shoulder uh does I'm sorry does contribute to uh the shoulder movement the next one is AC joint um it's the uh chromio cicular joint it's uh it's the chromian on the scan will form a joint space with a cicle okay again it is also um a three AIS of movement okay and the range of motion is really tiny as well and um what you need to know is um again the ligament that kind of provide the stability of the um joint the first one is between the cavico and uh the AC chromian it's a chromal cicular ligament right here and then the next one is the coral uh which is U Coral process and link to the acroman um that ligament is called aoral um acromial ligament right here and then and uh and then the the Cor process has the ligament that link to the cavico so it's um the coral clavicular ligament so you can kind of see within this tiny space there are so many um well three at least um ligament that keep um the SC joint um stable however when a person have um a outstretch u fall um typically um well not typically easily uh they can um hurt the or uh damage the joint's Spas then um this person's shoulder movement will be uh compromised and a lot of time uh it's it's it can be hard to diagnose because you know again people put more attention to the GH joint and uh and it's so hard for Li at this region to heal because we constantly move and the ligament are kind of on duty at every movement so it's really uh it take a long longer time than um like the elbow or the finger joint to heal okay so this is uh another ankle of um the AC joint you see here this uh this is the scaba it has an anle on the thoracic so and this is typically called um um the scal thoracic articulation right here because the SC is going to move along the rib okay and what I need you uh to see is uh this one uh Coral chromian ligament right here so this is coral process this is um chromian so this ligament kind of form the roof for U the GH joint right here so you can kind of see that for the shoulder girle it really um well in addition to the joint space um um um the AC joint and the SC joint can rely heavily on ligament to provide um stability okay and then the shoulder GTO motion it's really the combination of the scaba and the cical so um but in you know when we combine the two um U movement roughly we uh we call it scaba but it's really uh the scava and the clav U um and and and the clavical movement um together so um so we have scapular elevation depression we have um scapula protraction and retraction or scapula abduction and adduction and we have scab upward rotation and downward rotation I'm sorry upper rotation and downward rotation so you see when we when we call it upper rotation we really look at the the lbum right here so going to facing up that's upper rotation if it face down that's um downward rotation if you do um um the retraction or addaction like you know to the end range or Recon each and kind kind of try to touch um your um the border of the um scapula uh we may have some kind of scab tilt okay or if when we when the G joint do on the hyper um extension of the shoulder uh at the end range and the scapular will have some kind of um tilt and that's called scab tilt but that's not uh but that's not a typical uh movement that we uh refer to uh the scaer movement so again um your focus should be um for the six movement of the scabin elevation depression protraction retraction upward rotation and downward rotation okay