Muscles that Act on the Arm OIAs

Question 1

pectoralis major

Answer 1

O: clavicle, sternum, and costal cartilages of upper ribs
I: greater tubercle of humerus
A: flexes, adducts, and medially rotates arm

Question 2

latissimus dorsi

Answer 2

O:
I:
A: extends, adducts, and medially rotates arm

Question 3

deltoid

Answer 3

O: clavicle, acromion process, and spine of scapula
I: deltoid tuberosity of humerus
A: abducts, flexes and extends, medially and laterally rotates arm

Question 4

supraspinatus

Answer 4

O: supraspinous fossa of scapula
I: greater tubercle of humerus
A: abducts arm and stabilizes glenohumeral joint

Question 5

infraspinatus

Answer 5

O: infraspinous fossa of scapula
I: greater tubercle of humerus
A: laterally rotates arm and stabilizes glenohumeral joint

Question 6

subscapularis

Answer 6

O: subscapular fossa of scapula
I: lesser tubercle of humerus
A: medially rotates arm and stabilizes glenohumeral joint

Question 7

teres minor

Answer 7

O: axillary border of scapula
I: greater tubercle of humerus
A: laterally rotates and adducts arm and stabilizes glenohumeral joint

Question 8

teres major

Answer 8

O: inferior angle of scapula
I: intertubercular groove
A: adducts, extends and medially rotates arm

Question 9

coracobrachialis

Answer 9

O: coracoid process of scapula
I: medial surface of humerus
A: flexes and adducts arm