and one other thing I want um to talk about is Rotator C uh Rotator CU it's well it's really for muscles U that can of form and attach to the human head um to stabilize to help stabilize the GH joint um if you look at this U four muscles uh you see here we have supinatus and infraspinatus and then Terrace minor you see that um uh that um G geography um location and then uh in the front we have sub scapularis right here so um there's a synon called sits so s i t s um these four muscle um form um kind of kind of insert surround the hmer head and so that they got a name called Rotator CU but they each have different function to uh the shoulder movement um so uh don't get confused for that and one other um motion is called scaption um um it's really the um it's moving along the scapular plan so what is the scapular plan um if you look at and remember I talk about the ankle between this uh the thoracic region and and a scapula and that's called uh the scapula plan okay so it's not pure from the frontal plan because it's going to be going to interiorly about for about at 30° um so that's that kind of um it's kind of 30° to the frontal plane and that movement is called um scaption so you see this lady right here so when she uh um abduct um to uh about 30° and then raise up her arm that's called um scaption you kind of you can of raise your arm at diag diagonally like about 30° okay um this is uh this mostly used in uh rehab uh professionals and uh nowadays like the PT they don't they don't really use it a lot so you will hear this term scaption more um within the OT um so don't get surprised that you know some PD like what is that so it's just uh it's just a term and that uh we describe um and why do we uh want to know the scaption or 30 Dees of horizontal um abduction because um it kind of put the muscle um in more um secure or safe position when we move so it's it's secure it's a secure movement when we um train our patient um for the shoulder movement especially for the rotator cuff um injury uh it's it's kind of safe a lot of time a lot of time okay so it's kind of safe for us to move their arm in this direction so that's um scaption so um um I need to talk One More Concept so we talk about the shoulder girdle and the shoulder joint and uh in the beginning I I I said that uh really uh when we measure the shoulder movement we are measuring the combination of uh movement from shoulder girdle and shoulder joint so um so we need to know we need to know that so when you do the evaluation say R of motion evaluation um you need to know you need to make sure that schedule is okay you you not your attention should not just on the GH joint um you also need to check the scab to see if um scab going to move along um um to to get the full range of motion okay and then we will um U learn that in the lab okay um but um here's a table that kind of kind of show that how uh the shoulder joint and shoulder girdle kind of work together for example uh when a person um um want to do shoulder flexion uh then in in this time U the shoulder girdle will will kind of come um kind of help um upward rotating the shoulder um GLE to uh compl to to finish um the shoulder flexion okay and uh the um projection as well okay and uh when this person uh want to do a shorter extension and then the scapula will be uh doing downward rotation and retraction to uh to finish to help finish that when this person uh is doing a hyper extension kind of to the end then um scab til will happen and um and then and all that and I want to talk and I I also want to talk about um scaba humoral Rhythm um it's it's it's the um ratio between the shoulder joint and the shoulder girdle where especially for shoulder flexion and shoulder abduction okay and there's a a rhythm the ratio 2: one for GH joint to the scab movement so what really um is the rhythm again it's debate uh but roughly um people um agreed that there is a 2:1 ratio so what uh it really um um kind of occurred when the person's doing um I have example here for the shoulder abduction um here um from U for the first 30° of shoulder flexion or shoulder u a ruction is purely um the GH joint movement because at this time the scab muscle will be doing isomatric contraction to you know they need to St uh stabilize the scal first so that uh the human can can do can move the humoral bone and then when it pass the 30° uh the scab muscles start to do concentric contraction depending on the movement of the shoulder joint either downward or upward rotation or projection uh retraction okay um but in the end the final motion say uh this person just finished a 180 degrees of shoulder abduction um there's because of that 2:1 ratio so um 120° U is count is um it's done by the G joint and and the rest uh 60° is done by the scaba but within this um 60° 30 um came from the AC joint and 30 came from the SC joint so together they kind of contribute to u u the shoulder abduction okay so this is one example for shoulder abduction and it's it's the same ratio for the shoulder flection however um the uh country the the um the AC joint and SC joint they are contribute differently in flection okay so but I I you don't need to uh kind of separate the uh movement from AC and SC joint this is just give you some example that because of that U um location and the muscle I'm acting um all joints work together but they contribute differently but roughly there's a scapular soric I'm sorry scapular humoral Rhythm um like um GH joint movement versus scab movement um has a ratio of 2: one okay um so we we talk about the structure of the um um shoulder complex U mostly uh there's a lot of ligament kind of secure um The Joint the GH joint um and because of the end muscles and because um The Joint it's it's very mobile so uh and it it can be really easy uh to to injure it so I here are some common uh shoulder uh disease or pathologies that uh uh we see um you know commonly in a clinic um like uh the bone fracture um dislocation uh is very um um common for uh people with uh stroke especially U um like hypot tone or hyper uh tone and impingment syndrome uh it's a compression between the chromium Arch and the humoral head um it's Mo a lot of time people um have this U for um suos spinus or deltoid problem and Rotator cough um because we use uh suos spinus a lot like um it has huge role in shoulder abduction that we talk about so um uh suos spaus is one of the most common uh injury for uh torn uh rotator cuff and we also talk about a ligament and in the BSA so it's very easy when the people got hurt uh it's very PE easy for the person to develop forward and shoulder and bpal tendonitis is specifically for the biceps long head again it's it has major role in shoulder abduction and we human use that a lot use that movement a lot so uh when overused or when used in a not so good position uh people tend to hurt and um and the injury May occurred but um this is the shoulder complex um I hope um you have have a better understanding for the shoulder girdle and the shoulder joint and its structure and uh related to U the ligaments muscle function and um pathologies thank you