Posterior Shoulder Flashcards
muscle option for breast reconstruction
lat- can be resected in the back and brought around to anterior
flexion/extension of shoulder
flexion- out anteriorly in front of body
extension- behind posteriorly
the scapula ____ when the arm is abducted
laterally rotates- think about inferior angle rotating laterally
serratus anterior attachment, fn, innervation
inserts into anterior medial border of scapula
stabilizes scapula, laterally rotates, protracts (boxers muscle)
innervated by long thoracic, runs on superficial surface of muscle
cause of winged scapula
trauma to long thoracic nerve, unable to clamp scapula against thoracic wall
reduced ability to abduct arm above head w/o suffieicnt lateral rotation of scapula (loss of serratus anterior)
also possible from damage to CN XI and trapezius weakness
superficial posterior shoulder muscles and innervation
trapezius- innervated by CN XI
latissimus dorsi- C6,7,8 roots of thoracodorsal nerve
deep posterior shoulder muscles (3) fn and innervation
levator scapulae- lifts scapula
rhomboids major and minor- retract scapula toward spine
innervated by dorsal scapular nerve from C5 root
scapulohumeral muscles (6) and overall fn
deltoid teres major supraspinatus infraspinatus subscapularis teres minor
move shoulder joint and help stabilize head of humerus in glenoid
deltoid insertion, fn, innervatio
inserts into deltoid tuberosity on humerus
principle abductor of arm after initiation by supraspinatus
axillary nerve from C5 and 6
cause and consequences of axillary nerve damage
can be from surgical neck fractures
atrophy of delt and loss of shoulder contour
inability to abduct arm, loss of sensation in lateral aspect of shoulder (loss of superior lateral cutaneous nerve branch of axillary)
teres major insertion, fn, innervation
inserts into medial lip of inertubercular groove of humerus
adducts, extends, medially rotates arm (like lats)
lower subscapular nerve from C5 and 6
4 rotator cuff muscles
all intrinsic to shoulder
- supraspinatus
- infraspinatus
- teres major
- subscapularis
tendons insert and enforce the shoulder joint capsule, musculotendinous rotator cuff
supraspinatus
from supraspinous fossa and inserts into greater tubercle- initiates 15 degrees of abduction
suprascapular nerve C5,6
infraspinatus
infraspinous foss, inserts greater tubercle
lateral rotation
suprascapular C5,6
teres minor
lateral border of scapula and inserts into greater tubercle, lateral rotation
axillary nerve
insertion of posterior rotator cuff muscles
greater tubercle
subscapularis muscle
from subscapular fossa and inserts into lesser tubercle
medially rotates and adducts arm
upper and lower subscapular nerves C5, 6
3 muscles that adduct and medially rotate
subscapularis, lat, teres major
subacromial space
small space under acromion and above supraspinatus, this muscle must be able to slide w/i space
has bursa to help glide during abduction of arm
subacromial bursa location and fn and patho
technically two bursae- subarcromial and subdeltoid
synovial sacks reduce friction b/w muscle and bone
subacromial bursitis- inflammation from overuse, pain as bursa is impinged during abduction
most common tendonitis of rotator cuff
supraspinatus- due to irritation and impingement in subacromial space (overuse like swimming)
most common torn muscle of rotator cuff
supraspinatus
suprascapular notch location, contents
superior border of scapula, made a foramen by superior transvers scapular ligament
suprascapular nerve passes thru foramen, innervates supra and infraspinatus
suprascapular artery passes over ligament
boundaries, contents of quadrangular space
teres major below, teres minor above, long head of triceps left, surgical neck of humerus right (from posterior view)
contains axillary nerve, posterior circumflex humeral artery (vascularizes head of humerus)- can be damaged by surgical neck fracture
