Extrinsic Muscles of the Shoulder

Question 1

Where are the extrinsic muscles of the shoulder located

Answer 1

In the back

Question 2

Which muscles make up the superficial layer of the extrinsic muscle of the shoulder

Answer 2

Trapezius

Latissimus dorsi

Question 3

Which is the most superficial of all the back muscles

Answer 3

Trapezius

Question 4

Where does trapezius originate

Answer 4

Skull
Nuchal ligament
Spinous processses of C7-T12

Question 5

Where does trapezius insert

Answer 5

Clavicle
Acromion
Scapula spine

Question 6

Which nerves innervate trapezius

Answer 6

Accessory nerve

Also receives proprioceptor fibres from C3 and C4 spinal nerves

Question 7

What is the function of the upper fibres of trapezius

Answer 7

Elevate the scapula and rotates it during abduction of the arm

Question 8

What is the function of the middle fibres of trapezius

Answer 8

Retract the scapula

Question 9

What is the function of the lower fibres of trapezius

Answer 9

Pull the scapula infeiorly

Question 10

What is the most common cause of accessory nerve damage

Answer 10

Iatrogenic: -
Cervical lymph node biopsy
Cannulation of the internal jugular vein

Question 11

How do you test the accessory nerve

Answer 11

Test trapezius function - shrug shoulders

Question 12

What are the clinical features of accessory nerve damage

Answer 12

Muscle wasting and loss of function of trapezius
Partial paralysis of sternocleidomastoid
Asymmetrical neckline

Question 13

Where does latissimus dorsi originate

Answer 13

Spinous processes of T6-T12
Iliac crest
Thoracolumbar fascia
Inferior three ribs

Question 14

Where does latissimus dorsi insert

Answer 14

Tendon attaches to intertubercular sulcus of the humerus

Question 15

Which nerves innervate latissimus dorsi

Answer 15

Thoracodorsal nerve

Question 16

What is the action of latissimus dorsi

Answer 16

Extends
Adducts
Internally rotates upper limb

Question 17

Which muscles make up the deep layer of the extrinsic shoulder muscles

Answer 17

Levator scapulae
Rhomboid major
Rhomboid minor

Question 18

Where are the deep extrinsic shoulder muscles located

Answer 18

Underneath trapezius

Question 19

Where does levator scapulae originate

Answer 19

Transverse process of C1-4 vertebrae

Question 20

Where does levator scapulae insert

Answer 20

Medial border of the scapula

Question 21

What nerves innervate levator scapulae

Answer 21

Dorsal scapular nerve

Question 22

What is the action of levator scapulae

Answer 22

Elevates the scapula

Question 23

Where is rhomboid minor situated in relation to rhomboid major

Answer 23

Superiorly

Question 24

Where does rhomboid major originate

Answer 24

Spinous processes of T2-5 vertebrae

Question 25

Where does rhomboid major insert

Answer 25

Medial border of the scapula, between the spine and the inferior angle

Question 26

Which nerves innervate rhomboid major

Answer 26

Dorsal scapular nerve

Question 27

What is the action of rhomboid major

Answer 27

Retracts and rotates the scapula

Question 28

Where does rhomboid minor originate

Answer 28

Spinour processes of C7-T1

Question 29

Where does rhomboid minor insert

Answer 29

Medial border of the scapula, at the level of the spine of scapula

Question 30

Which nerves innervate rhomboid minor

Answer 30

Dorsal scapular nerve

Question 31

What is the action of rhomboid minor

Answer 31

Retracts and rotates the scapula