Muscle Actions Week 1 Superficial Back, Scapular and Pectoral Regions

Question 1

Latissimus Dorsi

Answer 1

Adduction, extension & IR of humerus

Question 2

Levator Scapulae

Answer 2

Elevation & downward rotation of the scapula

Question 3

Pectoralis Major

Answer 3

humeral adduction, flexion & medial rotation (sternocostal portion assists with extension of the flexed arm)

Question 4

Pectoralis Minor

Answer 4

anterior tilt of scapula; assists with depression of the shoulder & forced inspiration

Question 5

Rhomboids

Answer 5

scapular retraction, elevation (upper) & downward rotation of scapula

Question 6

Serratus Anterior

Answer 6

scapular protraction & scapular upward rotation

Question 7

Subclavius

Answer 7

depresses & stabilizes the clavicle

Question 8

Trapezius

Answer 8

scapular elevation (upper), scapular depression (lower), retraction (middle) & upward rotation (upper & lower)

Question 9

Deltoid

Answer 9

flexion & IR (anterior), abduction (primarily middle), extension & ER, horizontal abduction/extension (posterior) of humerus

Question 10

Supraspinatus

Answer 10

Initiates humeral abduction & ER humerus; stabilizes glenohumeral joint (reinforces superior aspect of joint capsule)

Question 11

Infraspinatus

Answer 11

ER of humerus; stabilizes glenohumeral joint

Question 12

Teres minor

Answer 12

ER of humerus; stabilizes glenohumeral joint

Question 13

Subscapularis

Answer 13

IR of humerus; stabilizes glenohumeral joint

Question 14

Teres Major

Answer 14

Adduction, IR, & Extension of humerus