Shoulder - muscle and joint interaction - exam 3

Question 1

what is the innervation of the SC joint

Answer 1

C3-C4 via cerviatl plexus

Question 2

what is the innervation of the GH and AC joints

Answer 2

C5-6 via the suprascapular and axillary nerves

Question 3

what nerves branch from the posterior cord of the brachial plexus

Answer 3

axillary
subscapular
throacodorsal

Question 4

what nerves are considered the proximal segments of the bracial plexus

Answer 4

dorsal scapular
long thoracic
pectoral
suprascapular

Question 5

what nerve supplies the deltoid and teres minor

Answer 5

axillary

Question 6

what are the nerve roots of the axillary nerve

Answer 6

C5-6

Question 7

what nerve supplies the latissimus dorsi

Answer 7

thoracodorsal

Question 8

what are the nerve roots of the thoracodorsal nerve

Answer 8

C6-8

Question 9

what nerve supplies the upper portion of the subscapularis

Answer 9

upper subscapular

Question 10

what nerve supplies the lower subscapularis and the teres major

Answer 10

lower subscapular nerve

Question 11

what are the nerve roots of the subscapular nerve

Answer 11

C5-6

Question 12

what nerve supplies the pectoralis major

Answer 12

lateral pectoral

Question 13

what nerve supplies the pectoralis major and pectoralis minor

Answer 13

medial pectoral

Question 14

what are the nerve roots for the pectoral nerve

Answer 14

C5-T1

Question 15

what nerve supplies the supraspinatous and infraspinatus

Answer 15

suprascapular

Question 16

what are the nerve roots for the suprascapular nerve

Answer 16

C5-6

Question 17

what nerve supplies the subclavius

Answer 17

subclavian

Question 18

what nerve supplies the rhomboids and levator scapula

Answer 18

dorsal scapular

Question 19

what are the nerve roots of the dorsal scapular nerve

Answer 19

C5

Question 20

what nerve supplies the serratus anterior

Answer 20

long throacic

Question 21

what are the nerve roots of the long thoracic nerve

Answer 21

C5-7

Question 22

describe proximal stabilizers

Answer 22

originate on spine/ribs/cranium
insert on scapula or clavicle

Question 23

describe distal mobilizers

Answer 23

originate on scapula/clavicle
insert on humerus/forearm

Question 24

what muscles are elevators at the ST joint

Answer 24

upper trap
levator scapulae
rhomboids

Question 25

what muscles are depressors at the ST joint

Answer 25

lower trap latissimus dorsi pec minor subclacius

Question 26

what muscles are protractors at the ST joint

Answer 26

serratus anterior

Question 27

what muscles are retractors at the ST joint

Answer 27

middle trap rhomboids lower trap

Question 28

what muscles are upward rotators at the ST joint

Answer 28

serratus anterior upper/lower trap

Question 29

what muscles are downward rotators at the ST joint

Answer 29

rhomboids pec minor

Question 30

if the upper trap, levator scapulae, and rhomboid lost their endurance/strength, what would happen to the scapula?

Answer 30

scapula depressed, protracted, and excessively downwardly rotated scapula

Question 31

t/f depression can raise the thorax if the arm is physically blocked or if the scapula is stabilized/fixed

Answer 31

true

Question 32

motions at the ST joint occur because of motions at...

Answer 32

SC and AC joints

Question 33

the clavicle elevates or rolls and slides opposite at what joint

Answer 33

SC

Question 34

what are the muscles that elevate the humerus at the GH joint

Answer 34

anterior/middle deltoid supraspinatus coracobrachialis biceps bracii

Question 35

if the deltoid is paralysed, can the supraspinatus still abduct the arm?

Answer 35

yes slide 20 lecture 10

Question 36

at 90 degrees abduction, humeral head stretches ____ ligament which acts like a hammock supporting the head of the humerus

Answer 36

ICL/axillary pouch

Question 37

active contraction pulls the capsule (tight/loose) to prevent it from being pinched between humeral head/acromion

Answer 37

tight

Question 38

upward rotators of the ST joint is essential for what motion of the UE

Answer 38

elevation

Question 39

what muscles are responsible for the upward drive and rotational adjustments of the scapula when elevating the UE

Answer 39

Serratus anterior upper and lower trap

Question 40

what muscle has the best leverage for UE upward rotation of the UE

Answer 40

Serratus anterior

Question 41

what muscles posteriorly tilt the scapula relative to the axis of rotation at the AC joint

Answer 41

serratus anterior and lower trap

Question 42

what muscles work to externally rotate the scapula relative to the axis of motion at he AC joint

Answer 42

serratus anterior and middle trap

Question 43

what are signs/symptoms that indicate weak traps

Answer 43

with full abd, t spine extends 10-15 degrees elevation can happen with difficulty getting high excessive protraction

Question 44

an injury of the long thoracic nerve can result in..

Answer 44

paralysis fo the right serratus anterior

Question 45

what signs/symptoms indicate weakness of the serratus anterior

Answer 45

downwardly rotated position scapula is anteriorly tilted and internally rotated

Question 46

describe scapular dyskinesis

Answer 46

any abnormal position/movement of the scapula

Question 47

what signs indicate scapular dyskinesis

Answer 47

reduced upward rotation excessive downward rotation, internal rotation, anterior tilt/elevation

Question 48

what are the 3 categories of scapular dyskinesis

Answer 48

type 1 - inferomedial border type 2 - entire medial border type 3 - superomedial border

Question 48

what are the 3 categories of scapular dyskinesis

Answer 48

type 1 - inferomedial border type 2 - entire medial border type 3 - superomedial border

Question 48

what are the 3 categories of scapular dyskinesis

Answer 48

type 1 - inferomedial border type 2 - entire medial border type 3 - superomedial border

Question 49

what is the purpose of the rotator cuff muscles

Answer 49

control dynamic stability and arthrokinematics of the GH joint

Question 50

what is the function of the supraspinatus during GH abduction

Answer 50

rolls the humeral head superiorly and toward abduction and compresses joint

Question 51

what muscles translate the humeral head downward to counteract superior translation

Answer 51

subscapularis infraspinatus teres minor

Question 52

during abduction of the GH joint, the internal moment arm is used by what 2 muscles

Answer 52

deltoid and supraspinatus

Question 53

what 2 muscles externally rotate humerus to increase clearance of greater tubercle and acromion

Answer 53

infraspinatus and teres minor

Question 54

how does the supraspinatus control the arthrokinematics of the GH joint during abduction

Answer 54

drives superior roll of humeral head compresses humeral head against glenoid fossa creates spacer above humeral head to restrict superior translation of humerus

Question 55

how does the infraspinatus/teres minor/subscapularis control the arthrokinematics of the GH joint during abduction

Answer 55

exert a depression force on humeral head teres minor and infraspinatus externally rotate humerus

Question 56

what muscles adduct and extend shoulder

Answer 56

posterior deltoid latissimus dorsi teres major long head of triceps brachii pec major infraspinatus teres minor

Question 57

what muscles stabilize the scapula during shoulder adduction and extension

Answer 57

rhomboids

Question 58

what muscles internally rotate the shoulder

Answer 58

subscapularis pec major latissimus dorsi teres major anterior delt

Question 59

what muscles externally rotate the shoulder

Answer 59

infraspinatus teres minor posterior delt

Question 60

t/f external rotation requires the scapula to be stable

Answer 60

true