Intrinsic muscles of the glenohumeral joint

Question 1

Where does deltoid originate?

Answer 1

Anterior: upper surface of lateral 1/3 clavicle.

Lateral: acromion process

Posterior: posterior border of spine of scapula

Question 2

Where does deltoid insert?

Answer 2

Deltoid tuberosity

Question 3

What innervates deltoid?

Answer 3

Axillary Nerve (C5, C6)

Question 4

What are the actions of deltoid?

Answer 4

Anterior: flexion

Posterior: retraction

All fibres: abduction

Question 5

Where does supraspinatus originate?

Answer 5

Medial 2/3 of supraspinous fossa

Question 6

Where does supraspinatus insert?

Answer 6

Most superior facet on the greater tubercule

Question 7

What innervates supraspinatus?

Answer 7

Suprascapular Nerve C5, C6

Question 8

What is the action of supraspinatus?

Answer 8

Abduction to 15 degrees

Question 9

Where does infraspinatus originate?

Answer 9

Medial 2/3 of infraspinous fossa

Question 10

Where does infraspinatus insert?

Answer 10

Middle facet on posterior surface of greater tubercule

Question 11

What innervates infraspinatus?

Answer 11

Suprascapular Nerve C5, C6

Question 12

What is the action of Infraspinatus

Answer 12

Lateral rotation

Question 13

Where does teres minor originate?

Answer 13

Upper 2/3 of lateral border of the scapula

Question 14

Where does teres minor insert?

Answer 14

Inferior facet of posterior surface of the greater tubercule

Question 15

What innervates teres minor?

Answer 15

Axillary Nerve (C6, C6)

Question 16

What is the action of teres minor?

Answer 16

Lateral Rotation

Question 17

What is the origin of teres major?

Answer 17

Lower part of lateral border of and inferior angle of the scapular

Question 18

Where does teres major insert?

Answer 18

Medial lip of the intertubercular groove

Question 19

What is the innervation of teres major?

Answer 19

Lower subscapular nerve (C5, C6)

Question 20

What is the action of teres major?

Answer 20

Medial rotation and extension, (but not hyper extension and adduction)

Question 21

What is the origin of subscapularis?

Answer 21

Subscapular fossa

Question 22

Where does subscapularis insert?

Answer 22

Lesser tubercle

Question 23

What is the innervation of subscapularis?

Answer 23

Upper and Lower subscapular nerves (C5, C6)

Question 24

What is the action of subscapularis?

Answer 24

Medial rotation