Arm muscles and Rotator cuff

Question 1

What is adduction?

Answer 1

Movement towards midline

add to the midline

Question 2

What is abduction?

Answer 2

Movement away from midline

think abduct… or take away

Question 3

Where is the deltoid?

Answer 3

From lateral ⅓ of clavicle, around the acromion and spine of the scapula and then all fibers insert on the deltoid tuberosity of the humerus

Question 4

What do the anterior fibers of the deltoid do?

Answer 4

Flex and medially rotate the arm

Question 5

What do the lateral fibers of the deltoid do?

Answer 5

Abduct the arm (away from midline)

Question 6

What do the posterior fibers of the deltoid do?

Answer 6

Extend and laterally rotate arm

Question 7

Where is the pectoralis major?

Answer 7

Medial ½ of clavicle and all of sternum to the humerus

Question 8

What does the pectoralis major do?

Answer 8

Flex, adduct, and medially rotate humerus

Question 9

What muscles form the axilla?

Answer 9

Anterior boder: pectoralis major

Posterior border: latissimus dorsi

Question 10

Where is the latissimus dorsi?

Answer 10

Vertebrae and iliac crest to humerus

Question 11

What does the latissimus dorsi do?

Answer 11

Extend, adduct, and medially rotate humerus

Question 12

What shape is the teres minor?

Answer 12

Round

Question 13

What does the teres major do?

Answer 13

Same as the latissimus dorsi.

Extend, adduct, and medially rotate humerus

Question 14

What is the “little lat”?

Answer 14

Teres major- does what the latissimus dorsi does, but is smaller

Question 15

Where is coracobrachialis?

Answer 15

Coracoid process to medial aspect on the shaft of the humerus

Question 16

What does the coracobrachialis do?

Answer 16

Flex and adduct the humerus

Question 17

Which muscles flex the humerus?

Answer 17

Deltoid, pectoralis major, coracobrachialis

Question 18

Which muscles extend the humerus?

Answer 18

Deltoid, latissimus dorsi, teres major

Question 19

What is the mnemonics for the rotator cuff muscles?

Answer 19

SITS- supraspinatus, infraspinatus, teres minor, subscapularis

Question 20

What do the muscles of the rotator cuff do?

Answer 20

Tendons of these 4 muscles merge to help hold the head of the humerus in the glenoid fossa, because the glenoid is a shallow depression.

Question 21

How can the rotator cuff be damaged?

Which muscle is most prone to injury?

Answer 21

Strenuous circumduction or hard blows to the shoulder, especially the supraspinatus

Question 22

What does the supraspinatus do?

Answer 22

Abduct the humerus

Question 23

What is a synergist of the supraspinatus?

Answer 23

Deltoid

Question 24

What does the infraspinatus do?

Answer 24

Extend and laterally rotate the humerus

Question 25

What movements does the teres minor do?

Answer 25

Extend, adduct, and laterally rotate humerus

Question 26

Which SITS muscle keeps the head of the humerus in the rotator cuff?

Answer 26

Teres minor

Question 27

What does the subscapularis do?

Answer 27

Medial rotation of humerus