L6: Muscles of the Shoulder Girdle

Question 1

name the scapula stabilizers

Answer 1

SARTL - serratus anterior, rhomboids (minor, major), traps, levator scapula

Question 2

which rotator cuff muscle works with the delts to abduct the arm

Answer 2

supraspinatus

Question 3

which of the rotator cuff muscles steer the glenoid fossa over to the head of the humerus vertically and horizontally?

Answer 3

vertically — supraspinatus

horizontally — infraspinatus, subscapularis, teres minor

Question 4

the brachial plexus ranges from what nerves?

Answer 4

anterior branches of spinal nerves C5-T1

Question 5

muscles of the shoulder girdle form what layer of the back

Answer 5

superficial

Question 6

these muscles can be classified based on their connection to what specific structures?

Answer 6

upper limb to thor wall; UL to vert column; scapula to humerus

Question 7

name the 4 muscles that connects the UL to the thor wall, and together, what do they form?

Answer 7

pec major &minor, subclavius, serratus ant

together they form the pectoral muscles

Question 8

actions of the pec major

Answer 8

arm ADD; arm FLEX; IR of arm

Question 9

origin and insertion of subclavius

Answer 9

origin: 1st cc; insertion: clavicle

Question 10

origin, insertion, action of serratus ant

Answer 10

origin: ribs 1 to 8
insertion: inf border & medial angle of scapula
action: upward rotation of scapula, scapula protraction

Question 11

the levator scapulae acts to ____ and has a fiber orientation of ___

Answer 11

action: elevates the scapula

fiber orientation: inferolaterally

Question 12

what’s the fiber orientation of rhomboid minor & major, and how do they move the scapula?

Answer 12

inferolaterally; they both raise the scapula upward & medially

Question 13

aside from their indiv functions, what do the rotator cuff muscles do to stabilize the shoulder joint?

Answer 13

they bring the humeral head towards the glenoid fossa to increase stability of GH joint

Question 14

which muscle is a pure forearm flexor, and how did it become one?

Answer 14

brachialis; since its insertion (coronoid proc of ulna) is closes to the elbow joint, and it doesn’t attach to the scapula (it’s origin is the ant inf half of humerus)

Question 15

which forearm flexor also acts as a pronator & supinator, what makes it able to do so?

Answer 15

biceps brachii; its attachment to the radius (specifically, its insertion at the radial tuberosity & bicipital aponeurosis) allows it to pronate & supinate the arm.

Question 16

insertion of the forearm extensor muscles

Answer 16

olecranon proc of ulna

Question 17

origin & insertion of rhomboids major & minor

Answer 17

origin:

• minor: ligamentum nuchae, spines C7 & T1
• major: spines T2-T5

insertion: medial bor. of scapula

Question 18

name the 5 muscles that connect the UL to the vert column

Answer 18

trapezius, latissimus dorsi, levator scapulae,

rhomboids major & minor

Question 19

name the 6 muscles connecting the scapula to the humerus

Answer 19

delts, supraspinatus, infraspinatus,

teres minor & major, subscapularis

Question 20

which rotator cuff muscles insert at the greater tuberosity

Answer 20

supraspinatus, infraspinatus, teres minor

Question 21

among the 5 extrinsic shoulder muscles (these connect the UL to the vert column), which acts to EXT, ADD, & MR arm?

Answer 21

Lats

Question 22

action of the subscapularis

Answer 22

IR of arm

Question 23

which rotator cuff muscles act to ER arm

Answer 23

infraspinatus, teres minor

Question 24

action of the pec major

Answer 24

arm ADD, FLEX, IR

Question 25

which pec muscle (muscles that connect the UL to the thor wall) inserts at the coracoid proc of the scapula

Answer 25

pec minor

Question 26

which of the 5 extrinsic shoulder muscles insert BOTH at the clavicle & the scapula?

Answer 26

trapezius

• upper fibers => lat third of the clavicle
• mid & lower fibers => acromion & spine of scapula

Question 27

as a group, the scapula stabilizers are involved with motions at the ____ articulation. Why is this important?

Answer 27

scapulothoracic

it’s needed for the shoulder complex to have normal biomechanics

Question 28

The serratus anterior & the trapezius help in the ____ of the scapula in varying degrees.

Answer 28

upward rotation

Question 29

2 muscles that connect the scapula to the humerus move the ___ while the rest ___ it

Answer 29

GH joint; stabilize

Question 30

the biceps brachii is found at the __ side of humerus and attach to the ___ of radius

Answer 30

ant

bicipital tuberosity

Question 31

due to its wide range of insertion, the biceps brachii can do lots of actions, namely?

Answer 31

elbow & shoulder flexion

forearm supination

Question 32

which extrinsic shoulder muscles insert wt the med bor. of scapula

Answer 32

rhomboid major & minor, levator scapula

Question 33

if scapula is fixed, the pec minor ___ the scapula

Answer 33

elevates

Question 34

Muscles that extend the shoulder

Answer 34

Delts; triceps brachii (long head); teres major; lats

Question 35

the 2 intrinsic shoulder muscles that abduct the arm

Answer 35

delts; supraspinatus

Question 36

origin & insertion of levator scapula

Answer 36

origin: TPs of C1-C4
insertion: superior angle of the medial border of the scapula