Muscles of the Scapula Region

Question 1

What are the muscles of the scapula?

Answer 1

Supraspinatus
Infraspinatus
Teres minor
Teres major
Subscapularis

Question 2

Origin of the supraspinatus

Answer 2

Supra-spinous fossa of the scapula

Question 3

Insertion of the supraspinatus

Answer 3

Greater tubercle of the humerus

Question 4

Nerve supply of the supraspinatus

Answer 4

Supra-scapular nerve [C5,C6]

Question 5

Action of the supraspinatus

Answer 5

Initiation of abduction of arm (0-15°) at shoulder joint

Question 6

Origin of the infraspinatus

Answer 6

Infraspinous fossa of the scapula

Question 7

Insertion of infraspinatus

Answer 7

Greater tubercle of the humerus

Question 8

Nerve supply of infraspinatus

Answer 8

Supra-scapular nerve [C5,C6]

Question 9

Action of infraspinatus

Answer 9

Lateral rotation of arm at the shoulder joint

Question 10

Origin of teres minor

Answer 10

Upper 2/3 of lateral border on the posterior surface of the scapula

Question 11

Insertion of teres minor

Answer 11

Greater tubercle of the humerus

Question 12

Nerve supply of teres minor

Answer 12

Axillary nerve C5,6

Question 13

Action of teres minor

Answer 13

Lateral rotation of arm at the shoulder joint

Question 14

Origin of teres major

Answer 14

The lower 1/3 of the lateral border of the posterior surface of the scapula

Question 15

Insertion of teres major

Answer 15

Medial lip of the inter-tubercular groove

Question 16

Nerve supply of teres major

Answer 16

Lower subscapular nerve

Question 17

Action of teres major

Answer 17

Medial rotation, adduction and extension of the arm at the shoulder joint

Question 18

Origin of subscapularis

Answer 18

Subscapular fossa

Question 19

Insertion of subscapularis

Answer 19

Lesser tubercle of humerus

Question 20

Nerve supply of subscapularis

Answer 20

Upper & lower subscapular nerve

Question 21

Action of subscapularis

Answer 21

Medial rotation & adduction

Question 22

Origin of the deltoid muscle

Answer 22

Inferior edge of the crest of the spine of the scapula
Lateral border of the acromion
Anterior border of lateral 1/3 of clavicle

Question 23

Insertion of the deltoid muscle

Answer 23

Deltoid tuberosity of humerus

Question 24

Nerve supply of deltoid muscle

Answer 24

Axillary nerve

Question 25

Action of deltoid muscle

Answer 25

**Anterior fibers**: Flexes & medially rotates the arm. **Middle fibers**: Abduct the arm from 15 to 90 degree. **Posterior fibers**: Extends & laterally rotates the arm

Question 26

What are the spaces of the scapular region?

Answer 26

Posterior quadrangle space Upper triangular space Low triangular interval

Question 27

What forms the borders of the posterior quadrangle space?

Answer 27

**Superiorly**: teres minor **Inferiorly**: teres major **Laterally**: humerus. **Medially**: long head of triceps brachii

Question 28

What are the contents of the posterior quadrangle space?

Answer 28

Axillary nerve Posterior circumflex humeral vessels

Question 29

What forms the borders of the upper triangle space?

Answer 29

**Superiorly**: teres minor. **Inferiorly**: teres major. **Laterally**: long head of triceps brachii.

Question 30

What are the contents of the upper triangular space?

Answer 30

Circumflex scapular vessels

Question 31

What forms the borders of the lower triangular interval?

Answer 31

**Medially**: long head of triceps brachii. **Laterally**: the shaft of the humerus. **Superiorly**: teres major.

Question 32

What are the contents of the lower triangular interval?

Answer 32

Radial nerve Profunda brachii artery