Posterior Shoulder Flashcards
scapula overlies which ribs
2nd-7th ribs
how many muscles attach to the scapula
16
where does the scapula articulate
clavicle at acromion and head of the humerus
head of humerus articulates with
glenoid cavity of the scapula
common site of humeral fractures
surgical neck
abduction of the arm above the head requires ____ rotation of the scapula
lateral
structures and function
serrates anterior muscle (boxers muscle)
stabilizes the scapula, laterally rotates the scapula, and protracts the scapula
innervation of serrates anterior muscle
long thoracic nerve (C5, C6, C7)
damage to the long thoracic nerve can render the serrates anterior weakend/paralyzed resulting in
winging of the scapula
superficial posterior shoulder muscles
trapezius and latissimus dorsi
deep posterior shoulder muscles
levator scapula rhomboids (major and minor)
scapulohumeral muscles
- deltoid - teres major - supraspinatus - infraspinatus - subscapularis - teres minor
function of scapulohumeral muscles
move the shoulder joint/arm and help stabilize the head of the humerus within the shallow glenoid cavity
innervation of deltoid
axillary nerve C5 and C6
axillary nerve can be injured in _________ of humerus
surgical neck fractures
muscles of the rotator cuff
supraspinatus infraspinaturs teres minor (small t) subscapularis “SItS”
most commonly inflamed tendon of the rotator cuff
supraspinatus due to its passage through the small subacromial space
fractures of the proximal humerus (surgical neck) can damage the ______ resulting in deltoid paralysis/weakness
axillary nerve
deep posterior shoulder muscles
levator scapula rhomboids (major and minor)
deep shoulder posterior muscles are innervated by the
dorsal scapular nerve C5 (some from C4)
scapulothoracic joint
concept of scapula sliding along thoracic wall to abduct and adduct the humerus
abduction of the arm above the head requires ____ rotation of the scapula
lateral
large triangular shaped muscle that forms the rounded contour of the sholder
deltoid
principal abductor of the arm
deltoid
first 15 degrees of abduction of the humerus
supraspinatus muscle
axillary nerve has a small branch that supplies sensation to the
lateral shoulder skin area
thick, round muscle located on the inferolateral aspect of the scapula
teres major
motion of teres major
adducts, extends and medially (internally) rotates the arm (same as lats)
innervation of teres major
lower sub scapular nerve (originates from c5 and c6)
supraspinatus and infraspinatus innervated by
suprascapular nerve (C5-C6)
teres minor innervation
axillary nerve
subscapularis innervation
upper and lower sub scapular nerves (C5 and C6)
subacromial bursa
synovial fluid sacks that help reduce friction between muscles/bones and allows the supraspinatus tendon to glide smoothly beneath the acromion during shoulder movements
subacromial space is small so prone to
shoulder bursitis or subacromial bursitis, inflammation of the bursa often from overuse, results in pain as the bursa get impinged during abduction
rotator cuff tendonitis
repetitive movements cause inflammation of the supraspinaturs (most commonly told) or in rotator cuff
passageways that allow neuromuscular structures to traverse between anterior and posterior scapular/arm regions
supra scapular notch triangular space quadrangular space triangular interval
quadrangular space boundaries
teres major teres minor both heads of the triceps surgical neck of the humerus
what nerve is housed in the quadrangular space?
axillary nerve
what nerve is housed in the suprascapular notch?
supra scapular nerve passes through this foramen and innervates the supraspinatus and infraspinatus muscles
spans the roof of the suprascapular notch forming a foramen
superior transverse scapular ligament
label and nerve innervation?
A = traps - CN XI
B = erector spinae
C= latissimus = thoracolumber C6,C7,C8
which muscle laterally rotates the scapula?
serratus anterior
which muscles produce external lateral rotation of the shoulder?
infraspinatus and teres minor
which artery traverses the surgical neck of the humerus?
posterior humeral circumflex
innervation of rhomboids
dorsoscapular nerve
