Intrinsic Muscles Of Shoulder

Question 1

What are the intrinsic muscles of shoulder?

Answer 1

Deltoid and teres major

Question 2

Origin of deltoid

Answer 2

Lateral 1/3 of clavicle, acromion, spine of scapula

Question 3

Insertion of deltoid

Answer 3

Deltoid tuberosity

Question 4

Action of deltoid

Answer 4

Anterior fibres- flexion and medial rotation
Posterior fibres- extension and lateral rotation
Middle fibres- major abductor of arm (15-90)

Question 5

Innervation of deltoid

Answer 5

Axillary nerve

Question 6

Origin of teres major

Answer 6

Posterior surface of inferior angle of scapula

Question 7

Insertion of teres major

Answer 7

Medial lip of intertubercular groove of humerus

Question 8

Action of teres major

Answer 8

Adducts and extends at shoulder, medially rotates arm

Question 9

Innervation of teres major

Answer 9

Lower subscapular nerve