Scapular and AA Muscle Actions

Question 1

latissimus dorsi

Answer 1

adduction, extension, and medial rotation of humerus

Question 2

levator scapulae

Answer 2

elevation and downward rotation of scapula

Question 3

pectoralis major

Answer 3

-humeral adduction, flexion, and medial rotation
-sternocostal portion assists with extension of flexed arm

Question 4

pectoralis minor

Answer 4

-anterior tilt of scapula
-assists with depression of the shoulder and forced inspiration

Question 5

rhomboids

Answer 5

scapular retraction, elevation, and downward rotation

Question 6

serratus anterior

Answer 6

scapular protraction and upward rotation

Question 7

subclavius

Answer 7

depresses and stabilizes clavicle

Question 8

trapezius

Answer 8

-scapular elevation (upper)
-scapular depression (lower)
-scapular retraction (middle)
-scapular upward rotation (upper and lower)

Question 9

deltoid

Answer 9

-anterior: flexion and medial rotation of humerus
-middle: abduction of humerus
-posterior: extension, lateral rotation, horizontal extension of humerus

Question 10

supraspinatus

Answer 10

-initiates humeral abduction and laterally rotates humerus
-stabilizes glenohumeral joint

Question 11

infraspinatus

Answer 11

-lateral rotation of humerus
-stabilizes joint capsule

Question 12

teres minor

Answer 12

-lateral rotation of humerus
-stabilizes glenohumeral joint

Question 13

subscapularis

Answer 13

-medial rotation of humerus
-stabilizes glenohumeral joint

Question 14

teres major

Answer 14

-humeral adduction, medial rotation, and extension