A stable shoulder joint relies on both static stabilizers (labrum, ligaments) and dynamic stabilizers (rotator cuff muscles).

“so we get a lot of static stability in our shoulder from this this Superior inferior anterior and posterior labor and just to be clear Alton in a non-pathologic state when you have that you know that young person who has yet to be you know experiencing any trauma of the shoulder um is that a is that a contained space of fluid that is between those two cartilagenous surfaces of the glenoid fossa the humeral head fully contained because usually to have a suction you want there has to be a fluid that's sort of contains it or air that's incompressible which is technically fluid but I assume there is an aquous fluid that's normally in there absolutely yeah you have a nice viscous joint fluid in all of our joints like that that's a great question and yes you couldn't have that suction as soon as you poke a hole in that you lose that that so when a person has a subluxation um it doesn't necessarily uh tear the laum does it correct and that's another huge point that will it factors into our treatment recommendations and mechanisms of injury if you are a young woman playing soccer generally young young women have looser joints women in general have looser joints which is part of phys or difference in physiology but and actually because of the weird nature of the shoulders there are men as well who have super loose shoulders at Baseline born that way but in general if you think of someone who whether male or female who has super loose joints then they can sublux out in and out without tearing anything they just ride up over that because it's just Loosey Goosey so the tighter the shoulder is the more you have have to lose what happens to the fluid when they sublux nothing because they have just a more stay okay aive it's the ligaments the ligaments are stretchy and they and they're bigger it's more like a balloon that you've keep blowing up repeatedly so but if you have someone who has basically a pretty stable joint not Loosey Goosey and then they sublux the only way you can do that is either tearing the ligaments but usually you also tear the labram and what I mean by tearing the laum is you separate the laum the inner Arc from its hard bony cartilagenous perfectly fused attachment very strong it takes a massive Force to to dislocate the shoulder it actually does or perfect mechanics and so if you if you have the classic um you're reaching up to get a rebound and someone grabs your arm um and worked it backwards that's a leverage an unnatural leverage that the makes the head tend to go out this direction anteriorly inferiorly like this so the head is going to go down this way yes yeah it just it just leverages it out and that's also a vulnerability based on where the muscles attach right yes yes very much so and we'll get to that as this the dynamic stabilizers but man this this laborum is tough but it tears off this is the classic location where you tear the laum there okay and it takes either a small tear that then is repetitively increased in size just from aggressive but repetitive use or it takes a one-time significant dislocation the attachments of the four rotator cuffs are basically behind above like it's it's basically like you got a big one there kind of at 9:00 right that's a great question you ask perfect questions that I forget to cover so these are kind of the cross-sections of the muscles that are just outside so these Encompass and in in and enshroud the the joint and this is the cross-sectional muscle bellies and this is where they and then as they as you come further out toward the head which is out here they taper down and form the tendons yeah yeah and that's so important because no shoulder can be stable alone just by these static stabilizer the labrum and the ligaments and the ligaments kind of lie in between the labram and the rotator cuff in here so the when you're referring to a SLAP tear you know obviously slap stands for Superior labal anterior posterior yes exactly and that is up here that is the super and that's a an odd injury that we um um the first person that really taught this well to us”