Muscles That Move Arm

Question 1

Pectoralis major

Answer 1

Origin: clavicle, sternum, and costal cartilage of upper ribs

Insertion: inter-tubercular sulcus of humerus

Action: flexes shoulder, adducts and rotates arm medially

Nerve supply: pectoral nerve

Question 2

Teres major

Answer 2

Origin: lateral border of scapula

Insertion: inter-tubercular sulcus of humerus

Action: extends shoulder, adducts and rotates arm medially

Nerve supply: lower subscapular nerve

Question 3

Latissimus dorsi

Answer 3

Origin: spines of sacral, lumbar and lower thoracic vertebrae, iliac crest and lower ribs

Insertion: inter-tubercular sulcus of humerus

Action: extends shoulder adducts, and rotates arm medially or depresses and retracts shoulder

Nerve supply: thoracodorsal nerve

Question 4

Supraspinatus

Answer 4

Origin:supraspinous fossa of scapula

Insertion: greater tubercle of humerus

Action:abducts arm

Nerve supply: sub-scapular nerve

Question 5

Deltoid

Answer 5

Origin: acromion process, spine of the scapula and the clavicle

Insertion: deltoid tuberosity of humerus

Action: lateral portion adducts arm. Anterior portion flexes shoulder. Posterior portion extends shoulder

Nerve supply: axillary nerve

Question 6

Subscapular

Answer 6

Origin: anterior surface of scapula

Insertion: lesser tubercle of humerus

Action: rotates arm medially

Nerve supply: subscapular nerve

Question 7

Infraspinatus

Answer 7

Origin: infraspinous fossa of scapula

Insertion: greater tubercle of humerus

Action rotates arm laterally

Nerve supply: upper and lower subscapular nerves

Question 8

Teres minor

Answer 8

Origin: lateral border of scapula

Insertion: greater tubercle of humerus

Action: rotates arm laterally

Nerve supply: axillary nerve