Posterior Shoulder

Question 1

muscle option for breast reconstruction

Answer 1

lat- can be resected in the back and brought around to anterior

Question 2

flexion/extension of shoulder

Answer 2

flexion- out anteriorly in front of body

extension- behind posteriorly

Question 3

the scapula ____ when the arm is abducted

Answer 3

laterally rotates- think about inferior angle rotating laterally

Question 4

serratus anterior attachment, fn, innervation

Answer 4

inserts into anterior medial border of scapula

stabilizes scapula, laterally rotates, protracts (boxers muscle)

innervated by long thoracic, runs on superficial surface of muscle

Question 5

cause of winged scapula

Answer 5

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

Question 6

superficial posterior shoulder muscles and innervation

Answer 6

trapezius- innervated by CN XI

latissimus dorsi- C6,7,8 roots of thoracodorsal nerve

Question 7

deep posterior shoulder muscles (3) fn and innervation

Answer 7

levator scapulae- lifts scapula

rhomboids major and minor- retract scapula toward spine

innervated by dorsal scapular nerve from C5 root

Question 8

scapulohumeral muscles (6) and overall fn

Answer 8

deltoid
teres major
supraspinatus
infraspinatus
subscapularis
teres minor

move shoulder joint and help stabilize head of humerus in glenoid

Question 9

deltoid insertion, fn, innervatio

Answer 9

inserts into deltoid tuberosity on humerus

principle abductor of arm after initiation by supraspinatus

axillary nerve from C5 and 6

Question 10

cause and consequences of axillary nerve damage

Answer 10

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)

Question 11

teres major insertion, fn, innervation

Answer 11

inserts into medial lip of inertubercular groove of humerus

adducts, extends, medially rotates arm (like lats)

lower subscapular nerve from C5 and 6

Question 12

4 rotator cuff muscles

Answer 12

all intrinsic to shoulder

• supraspinatus
• infraspinatus
• teres major
• subscapularis

tendons insert and enforce the shoulder joint capsule, musculotendinous rotator cuff

Question 13

supraspinatus

Answer 13

from supraspinous fossa and inserts into greater tubercle- initiates 15 degrees of abduction

suprascapular nerve C5,6

Question 14

infraspinatus

Answer 14

infraspinous foss, inserts greater tubercle

lateral rotation

suprascapular C5,6

Question 15

teres minor

Answer 15

lateral border of scapula and inserts into greater tubercle, lateral rotation

axillary nerve

Question 16

insertion of posterior rotator cuff muscles

Answer 16

greater tubercle

Question 17

subscapularis muscle

Answer 17

from subscapular fossa and inserts into lesser tubercle

medially rotates and adducts arm

upper and lower subscapular nerves C5, 6

Question 18

3 muscles that adduct and medially rotate

Answer 18

subscapularis, lat, teres major

Question 19

subacromial space

Answer 19

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

Question 20

subacromial bursa location and fn and patho

Answer 20

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

Question 21

most common tendonitis of rotator cuff

Answer 21

supraspinatus- due to irritation and impingement in subacromial space (overuse like swimming)

Question 22

most common torn muscle of rotator cuff

Answer 22

supraspinatus

Question 23

suprascapular notch location, contents

Answer 23

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

Question 24

boundaries, contents of quadrangular space

Answer 24

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