so now let's look at the gleno humal joint or um AKA GH joint um it's very famous because you know uh people always um uh refer this GH joint to uh shoulder joint uh but you need to know that U the whole shoulder R of motion when we measure it it's really a combination of um shoulder girdle and the shoulder joint which is the whole shoulder compound and we will talk about that later but when we look at the GH Jo right here so um it's really uh the humal hand kind of form a joint space with the uh scapula and uh and then the joint space is uh a gleno fosa okay and it allows three degrees of freedom um um that allows flexion extension abduction adduction external and internal rotation and um horizontal U abduction and U adduction okay um The Joint um rely heavily on the muscles and the ligament and the capsule for uh stability again you need to know uh these ligaments and capsules okay so if you look at the ligament right here here um um here uh we have chical humoral ligament that kind of Link the U that kind of form the roof of the GH joint that we just talked about and then we have a gleno humoral ligament here um um we have Superior and middle and you don't need to um specify this if uh doing the pin test but you need you do need to tell me that this is uh a L humoral ligament right here okay um and surrounding um the ligaments we have Bersa on top of them so Bersa is really um some kind of um soft tissue and squeezy um um structure or tissue um we have S A chromium BSA it's under the acroman and then we have S um cutanous AC chromian burst that's really U around the uh AC chromian and we have um sub Coral um Bersa is really under the coral Praxis so you can see here the G joint is um surrounded or you know secure by um the ligaments and versa so when a person um um hurt the shoulder and um the Persona is easily got injured and and it's a it's a source for a nutrition and t uh if when people feel pain they um T not to move their um painful joint and and because of the immobilization the ligaments got um tightened a bit and then the BSA kind of being uh become stiff and um that's often times uh what what um people would end up um develop a frozen shoulder that's because it really it's really hard to move and when they move it's really painful you can see uh that's the result of not using U their uh shoulder and if you use too much that would also cause damage to the Bersa and then the ligament you can you kind of see here that uh a lot of friction going on and that's not good for the ligament and then the burst and again if you use too much then you U this person will um um develop um a painful shoulder as well so um the shoulder movement what are the muscles are kind of um um what are what muscles are contributing U to shoulder movement again uh um I find it helpful uh to look at the uh location the origin and insertion of the muscle and that to me is more easy uh much easier to um memorize those muscle function U for shoulder abductor um easily um um the middle deltoid um and the supraspinatus they're in the position that um can of do the Abduction the super spinus is a pure um shoulder abductor because you can get kind of P almost 90° to the humoral bone right here and the delto is interesting though because it's huge right here so when this muscle contract it can it can to elevate it can to elevate the um the the the bone then it may uh cause some kind of imp pinch impingment of the of the structure right here so um and then uh this one is on the L head of the um biceps so the L head of the bicep um going to kind of walk going to run through uh this uh groove of of uh the Bice um the the humoral B right here and when um our our shoulder is in external rotation that will bring this um tendon more to the lateral side that uh it's more in line with the shoulder abduction so if uh the the arm is in external rotation then the biceps long head will help doing the shoulder ABD ction so how does these three muscle um work together so at the early stage if okay so if no injury if this person is normal okay so uh at the early stage the suos spinus will uh will do the pure abduction and if the um um if the shoulder is in ex rotation then the bicep long head will help to um abducting the shoulder and when when it going to go like past about like 15 to 20° well the number is uh in debate so um that's why I didn't put the number in the slides uh but you know when this when when when the arm going to keep doing and that would lead the the uh delto to be a more uh Advantage position then the delto will kind of join uh the two muscles in doing a shoulder abduction so you can see you can see here so in the beginning it's more um the suos spinus and then the biceps kind of join together and then at the end is the delto and shoulder addaction is really uh to bring the U the humoral bone to the body so if you look at the muscle right here the muscle um contributing to shoulder um adduction is the PE major um and the terce um terce uh ma uh major and the T so if you look um from the back um this is uh yeah this is this is the back so this is U Terrace major right here and then the T the Tas door side is uh right below the terce M major I'm sorry I didn't uh put this number uh put this muscle right here but this is uh ter major and then the the T the T door side going to attach very close to the m terce major that's from the that's muscle for on the back you see that's these two muscle kind of pull the uh humoral bone to the body and from the front view the PEC major again on the sternals uh head kind the muscle kind of pull pull the humoral bone toward the body so these three muscles are working together for shoulder adduction for should flection um um so these uh these muscle are all contributing to should the flection but if you look at U the the U spatial relationship you you can kind of guess who is the primary um mover which is the anterior delto right here because the anterior delto kind of kind of directly raise up or do the flexion of the shoulder right here okay the Pegman help in doing so because you can see the muscle going to help doing that but it's not you know um in the very beginning um stage and coral Brach is also a shoulder flexor you see here um the insertion is right here origin is right here when this muscle um contract can help bring up the shoulder okay and again the biceps long head kind of run through um on the humal head right here so again when um when a person raise up the the arm the biceps long hand will help um doing the shoulder flexion shoulder extension U we looking for U muscle that uh kind of um bring the humoral head I'm sorry the humoral bone backward okay so for that we have posterior U deltoid we have um terce major um um and then the the tth store side um here I need to go back to uh the previous slide to show you the front of the front view right here um um it's hard to see it here um so you but here you can kind of see that the Terrace major kind of go a little bit to the front but not to the front you know a little bit to the front what what does that um tell us is when this muscle contract Contracting it'll bring the forearm backward okay and and so is the thetis dorsy or dors side okay and external rotation um U we looking for a muscle that attached you know to the lateral side so that when this muscle contract it it'll turn the humor head outward so we have infraspinatus and terce minor you see here on the major and minor they insert at the different spot of the humoral bone and then so that they function differently so terce minor um external rotate um the scaba I'm sorry the humoral bone and then um the Del the posterior Delta going to help a little bit but it's not a prime M okay so here uh again I like to use uh Lark so we see the scav spine right here uh we have elevator uh scaba we just talk about and then here here um we have this is spine right above the spine we have ramboy minor below the spine we have ramboy major so if you look at the scab right here above the spine is called supraspinatus we just talk about that and then below the spine that's infraspinatus so yeah so to me it's more U very easy to to me uh to memorize this muscle function okay um and um the internal rotation of the of the shoulder involve um um PE major Terrace Major latis D side and anterior deltoid again if you look at um the um the the location of the muscle um it's not hard to see um and one one musle um called subscapularis um that it's uh if you look at FR front front you see it's kind of on on the scaba and it attached to the humor hand right here so when this muscle um contract can of bring the humoral um bone inward so it also um contribute to the uh shoulder internal um rotation okay all right so these are the um um shoulder movement uh and muscle group for U responsible for the shoulder move again it can be a lot but if you look at the location if you think about the origin and insertion it's not too hard to understand uh their function the muscles function uh uh to the shoulder girdle and to the shoulder joint