Flashcards in Brachial plexus and shoulder Deck (12):
Rorator cuff muscles innervation and action
supraspinatus: innervated by suprascapular nerve. does initial arm abduction
infraspinatus: also innervated by suprascapular nerve (C5,C6). "pitching" muscle: lateral rotation
teres minor: innervated by the axillary nerve. adduction and lateral rotation
subscapularis: innervated by subscapular nerve. medial rotation and adduction
C5-C6 important for all
What causes impingement?
muscles don't pass smoothly under the acromion. associated with repetitive shoulder movements
What are the bones of the wrist?
so long to pinky, here comes the thumb: scafoid, lunate, triquetrum, pisiform, hamate, capatate, trapezoid, trapezium`
most common fracture. will cause pain in the anatomical snuffbox. can have avascular necrosis because of retrograde blood supply
What wrist fracture can cause acute carpal tunnel
What fracture can cause ulnar nerve injury?
hamate hook. often injured by falling on outstretched hand
What is the Guyon canal syndrome? Who gets it?
compression of the ulnar nerve at the wrist/hand. seen in cyclists
Draw the brachial plexus
see notes or online. should include long thoracic nerve from C5-C7. upper, medial, lower trunks; lateral, posterior, medial cords (C5/6 is lateral). axillial and radial from posterior cord; musculocutaneous from lateral cord, ulnar from medial cord, median from both lateral and medial
Erb's Palsy: what nerve is injured, how, and what muscles are affected. how does the patient look?
injury to the upper roots: C5 and C6. causes injury to the deltoid, SItS muscles, and musculocutaneous nerve. "waiter's tip position:"
Deltoid and supraspinatus injury: can't abduct arm; biceps injury: can't flex or supinate arm
infraspinatus injury: can't laterally rotate arm.
Injury occurs if neck and should are separated too much (trauma), or during birth
Klumpke palsy: what nerve is injured, how, and what muscles are affected. how does the patient look?
lower trunk injury (C8, T1). caused by pulling arm up during birth or grabbing a tree branch to break a fall. causes problems with the ulnar and median: intrinsic hand muscles, lumbricles, interossi, hypothenar, and thenar muscles. See a claw hand
Thoracic outlet syndrome: what nerve is injured, how, and what muscles are affected. how does the patient look?
problems with the lower trunk as it exits the throacic aperture. also compreses subclavian vessels. may be due to a rib injury or to Pancoast tumor. Like Klumpke palsy, causes atrophy of intrinsic hand muscles, but also ischemia, pain and edema from vascular compression