all right so let's continue with chapter four and we'll go into the muscles of chapter four so five muscles are primarily involved in shoulder girdle movements they all originate on the axial skeleton insert on the scapula and slash or the clavicle do not attach to the humerus and do not cause shoulder joint actions essential in providing dynamic stability of the scapula so it can serve as a relative base of support for the shoulder joint activity such as throwing batting and blocking so these are some good points about the muscles of the shoulder girdle scapular muscles important in spinal posture forward shoulders due to scapular protractors and depressures becoming stronger and tighter and retractors becoming weaker uh contribute to kyphosis less functional position for the glenohumeral joint important to maintain lumbar lordosis and keep the head over the trunk in a balanced position good posture enhances respiration inspiration scapular winging relatively rare but can affect normal function activity of the upper extremity most commonly affects the serratus anterior leading to medial winging when pushing forward or raising the arm serratus anterior weakness or paralysis is typically due to injury of the long thoracic nerve which may become from a variety of causes so this is definitely on the quiz much less common much less commonly the trapezius and slash or rhomboid may be affected leading to lateral winging i don't know why it says slash this should be slash as in a slash in the interpreted so there's no muscle called slash it should be actually a slash so here's scapular uh winging weakness in scapula cuts so that's what scapular winging that's weakness in the serratus anterior okay and then here's the injury in football where he actually injured the long thoracic nerve you can see this side is normal but the long thoracic nerve on this side is injured so it causes the winging of the scapula so whenever you see that on a patient or athlete you need to work the serratus anterior so here are the muscles so here's the scapula okay so in order for it to go up that's going to be rhomboids and traps upper and middle and then the levator is going to bring it up rhomboids middle and lower trap is going to bring it retraction forward is going to be serious anterior pec minor traps lower trap and pectoralis minor will also bring it down um trapezius middle lower will cause this rotation upward rotation downward rotation or rhomboids and pec minor so this is a great way to kind of see and here's a good reference point this elevation this adduction app duction depression upward rotation downward rotation so use this as a guide and then know what muscles will do what and those are excellent quiz questions okay remember this is a movement anatomy class we're concerned about what muscles are active during certain movements so we can pinpoint and help our athletes and clients so here's the serratus anterior again think about this and from anatomy class you would have had to memorize origin search and nerve supply you don't have to do that you just have to tell me location and actions and movement anatomy you should know the origin and insertion but i'm not going to quiz you on origin insertion because that's anatomy 101. so here's the pectoralis minor abduction downward rotation and depression subclavius does depression here's the traps and the posterior you've got upper fibers elevation extension head middle fibers elevation abduction upper rotation lower fibers adduction depression and upper rotation okay rhomboids adduction downward rotation and elevation and levator scap does elevation so knowing the actions of all these muscles is what you really want to know and that's what you study for this exam and for this class now as far as nerves are concerned again this goes back to anatomy but you should know which basic nerves uh do what social girdle muscles are permanently innervated by the cervical and the brachial plexus so anatomy probably had to draw the brachial plexus so it's a group of nerves that innervates the upper extremities so you look at some of these here's the dorsals or c4 c5 c6 c7 c8 remember you have seven cervical but you actually have eight cervical nerves here here's the dorsal scapular nerve super scapular nerve they c5 6 and 7 will form a certain cord again going back and looking at this now you're thinking oh man this is pretty complicated you probably have to review your brachial plexus i'm not again it's not an anatomy class where i'm going to ask you specifically what are the branches where the chords and the roots but you should know which nerve is innervated by which muscle to a certain extent that if something is damaged and i'll mention it and i'll highlight it so you can pay attention to that but don't don't feel like you have to learn the brachial plexus again you should be familiar with it but i'm not going to ask specifically specific questions on the brachial plexus so branches of c3 and c4 that's the trap in levator okay the spinal accessory nerve that's trap so dorsal scapular nerve levator and rhomboid so a good question on the quiz i could say is a overhead athlete such a pitcher or thrower has damage to their dorsal scapular nerve which muscles may be affected or which action may be affected right so knowing the muscle and actions would be important the long thoracic nerve originates from c5 c6 and c7 which is serratus anterior the medial pectoral nerve originates from c8 and t1 that's pec minor here's your trap again here's the origin and here's the insertion the origin insertion okay what does the levator scap muscle do it elevates the medial margin of the scapula it's a weak downward rotator and a weak a a deductor okay and there's the origin insertion again don't worry too much about origin insertion but you still need to know that i'm more concerned about the actions here rhomboids rhomboid muscle minor muscles work together adduction retraction draw the scapula toward the spinal column downward rotation from upward rotated position they draw the scapula in downward rotation causes elevation slight upward movement accompanying adduction so again the rhomboid muscles what do they do not so much the origin and insertion but make sure you know what they do and what action they have on the scapula serratus probably one of the most important muscles this is definitely beyond the quiz a-b-duction protraction draws the medial border of the scapula away from the vertebrae upward rotation longer lower fibers tend to draw the inferior angle of the scapula further away from the vertebrae thus rotating the scapula upward slightly so this is a great muscle i call this a bruce lee muscle if you look at bruce lee i mean he had the one-inch punch but look at this serratus ah that's great and these are lats right here but the serratus is unreal so the serratus uh allows him to do that one inch punch obviously the power came mostly from his hips but that little bit of protraction is all serratus pec minor if you have tightness in your pec minor you might get rounded shoulders you get a b duction protraction draws the scapula forward and tends to tilt the lower border away from the ribs it's a downward rotator as it a b ducts it draws the scapula downward depression when it and the scapula is rotated upward it assists in depression subclavius this is an interesting muscle it's just underneath the clavicle stabilization and protection of the sternoclavicular joint depression abduction here's the scapular ab duction scapula moves laterally away from the spinous process without rotation so scapular abduction would be a push-up and bench press that's scapular a b duction so the agonist would be pectoralis minor and serratus anterior so knowing okay what's an example of a movement that causes scapular abduction and then what are the agonists is the way that you would study that so remember push-ups in bench press pec minor serratus scapular abduction scapular adduction is occurs with retraction squeezing your shoulder blades together what does that middle trap lower trap and rhomboids okay so if you have forward shoulders you're going to want to work middle trap lower trap and rhomboids to get those shoulders back scapula's back upward rotation what causes upward rotation your male trap lower trap and serratus what causes downward rotation pectoralis minor and rhomboid so if what you can think is that okay if a patient or client is not able to do upward movement then what's going to be tight right so what's going to be weak so weakness would be in the middle trap lower trap and serratus but since if their downward rotators are trite such as the rhomboids and pectoralis minor then the ammo i might not be able to upwardly rotate so knowing what's weak and knowing what's right so you want to strengthen weak muscles and you want to stretch tight muscles scapular elevation lifting the scapula without rotation in anatomical position like a shoulder shrug what does shrugs levator upper trap middle trap and rhomboids scapular depression that would be in a dip so remember i showed you if you're sitting in a chair just push yourself up and that's lower trap and pec minor so you really want to work those lower traps and now if we look at you guys did some awesome emg studies and each emg has its own limitations most of them they don't really have a lot of um uh participants so they're limited but i've actually looked at some of those and i found i kind of picked up the the best ones here so if you look at upper trap we want to do rack pulls upper trap barbell shrugs middle trap i like the prone reverse flies lower trap you got the prone y's okay rhomboids rows pull-ups rhomboids chest supported rows and the best grip seems to be a thumbless grip wide and pronated for the shoulder girdle okay yeah let's look at some exercises and let's look at some videos here here's some websites the wheelist textbook of orthopedics is a good one and it's baseball almanac diana here since just some good websites that you can look at diagnose treatment of snapping scapula sternoclavicular joint injuries ac joint injuries ac joint injuries okay