Shoulder Flashcards
Three areas of transition in the UE
axilla
cubital fossa
carpal tunnel
all nerves and vessels of the arm pass through here
superior thoracic aperture
thoracic inlet, formed by first rib, posterior clavicle, superior margin scapula, medial coracoid process
thoracic inlet syndrome
first rib and clavicle compress nerves passing through superior thoracic aperture
What nerve roots form the brachial plexus?
C5-T1
terminal branches musculocutaneous, axillary, median, radial, ulnar nerves
only UE muscle not innervated by brachial plexus in trapezius, CN 11
Brachial plexus mnemonic
real truckers drink cold beer
roots trunks divisions cords branches
what does the radial nerve innervate?
posterior arm and forearm
elbow and wrist extensors
What does the ulnar nerve innervate?
intrinsic hand muscles and medial wrist flexors in forearm
what does the axillary nerve innervate?
deltoid and teres minor
what nerves could be impaired in humeral surgical neck fracture?
radial, ulnar, axillary
sternoclavicular joint bones and ligaments
clavicle, manubrium, cartilage of rib 1
posterior/anterior sternoclavicular, interclavicular, and costoclavicular ligaments
acromioclavicular joint bones and ligaments
acromion of scapula snd clavicle are a synovial joint
2 ligaments acrmioclavicular and coracoclavicular
coracoacromial ligament present but has no role in stabilizing the Ac joint
function of the coracoacromial ligament
superior arch over the humerus preventing superior displacement
glenohumeral joint
what kind of joint and where does it’s stability come from
ball and socket joint with high mobility
stability comes from glenoid labrum, rotator cuff muscles, extracapsular ligaments, long head of biceps tendon
function of the glenoid labrum
deepens ball and socket joint by 50%, main shoulder stabiltiy
What structures prevent downward displacement of the humerus?
supraspinatus pulls up, upper capsule, and coracohumeral ligament all pull the bone up
how does the rotator cuff increase shoulder stability
They pull the humeral head into the glenoid cavity
what structures prevent upward displacement of the humerus?
coracoacromial arch, long head of biceps
two most common rotator cuff disorders
tendinopathy and impingement
most commonly supraspinatus because it passes through the small joint space between the acromion and acromioclavicular ligament with limited blood supply
trapezius
origin: superior nuchal line, occipital protuberance, C7-T12 spinous processes
insertion: clavicle, acromion, scapular spine
innervation: CN 11
action: scapular elevation, retraction, depression
deltoid
origin: inferior scapular spine, lateral acromion, lateral clavicle
insertion: deltoid tuberosity
innervation: axillary
action: abduction, extension, flexion, IR, ER
starts same places trap inserts!
levator scapulae
origin: C1-C4 transverse processes
insertion: superior angle of scapula
innervation: dorsal scapular n
action: elevate and upward rotate scapula
rhomboid minor
origin: C7-T1 transverse processes
insertion: medial border above scapular spine
innervation: dorsal scapular n
action: retraction
rhomboid major
origin: T2-T5 transverse processes
insertion: medial border below scapular spine
innervation: dorsal scapular n
action: retract
supraspinatus
origin: supraspinous fossa
insertion: greater tubercle
innervation: suprascapular n
action: abduction
