Shoulder Muscles

Question 1

Deltoid innervation

Answer 1

Axillary nerve

Question 2

Deltoid actions

Answer 2

Anterior fibres – flexion and medial rotation.
Posterior fibres – extension and lateral rotation.
Middle fibres – the major abductor of the arm (takes over from the supraspinatus, which abducts the first 15 degrees).

Question 3

Teres Major innervation

Answer 3

Lower subscapular nerve.

Question 4

Teres Major actions

Answer 4

Adducts and extends at the shoulder, and medially rotates the arm.

Question 5

What are the rotator cuff muscles?

Answer 5

Supraspinatus
Infraspinatus
Teres Minor
Subscapularis

SITS muscles

Question 6

Innervation of Supraspinatus

Answer 6

Suprascapular nerve.

Question 7

Innervation of infraspinatus

Answer 7

Suprascapular nerve.

Question 8

Function of supraspinatus

Answer 8

Abducts the arm 0-15 degrees, and assists deltoid for 15-90 degrees

Question 9

Function of infraspinatus

Answer 9

Laterally rotates the arm

Question 10

Innervation of subscapularis

Answer 10

Upper and lower subscapular nerves.

Question 11

Function of subscapularis

Answer 11

Medially rotates the arm.

Question 12

Innervation of Teres Minor

Answer 12

Axillary Nerve

Question 13

Function of Teres Minor

Answer 13

Laterally rotates the arm