Extrinsic Muscles Of The Shoulder

Question 1

What are the extrinsic muscle? (Why classes as this?)

Answer 1

Those that originate from the trunk and attach to the shoulder bones

Question 2

What are the superficial extrinsic shoulder muscles?

Answer 2

Trapezius and latissimus dorsi

Question 3

What are the deep extrinsic shoulder muscles? (3)

Answer 3

Levator scapulae
Rhomboid minor
Rhomboid major

(***All beneath the trapezoid)

Question 4

What are the attachments of the trapezoid?

Answer 4

Originates from the skull, nuchal ligament and spinous processes of C7-T12
Attached to the clavicle, acromion and scapula spine

Question 5

What nerve innervates the trapezoid?

Answer 5

Accessory nerve (plus proprioceptor fibres form C3 and C4 spinal nerves)

Question 6

What is the action of the upper fibres of the trapezoid?

Answer 6

Elevates the scapula and rotates it during abduction of the arm

Question 7

What is the action of the middle fibres of the trapezoid muscle?

Answer 7

Retract the scapula

Question 8

What is the action of the lower fibres of the trapezoid?

Answer 8

Depression of the scapula

Question 9

How can you test the accessory nerve?

Answer 9

By assessing the trapezoid function
- ask patient to shrug shoulders

There may also be muscle wasting of trapezoid-asymmetrical neckline

Question 10

What are the attachments of the latissimus dorsi?

Answer 10

Arises from the spinous processes of T6-T12, iliac crest, thoracolumbar fascia and inferior 3 ribs
Fibres converge to tendon which attached to inter-tubercular sulcus of the humerus (bicipital grove)

Question 11

What nerve innervates latissimus dorsi?

Answer 11

Thoracodorsal nerve

Question 12

What is the action of latissimus dorsi?

Answer 12

Extends, adducts and medically rotates the upper limb

Question 13

What is the attachment of the levator scapulae?

Answer 13

Originates from the transverse processes of the C1-C4 vertebrae and attaches to the medial border of the scapula

Question 14

What nerve innervates levator scapulae?

Answer 14

Dorsal scapular nerve and cervical nerve (C3-C5)

Question 15

What is the action of the levator scapulae?

Answer 15

Elevates (and rotates) the scapula

Question 16

Which of the two rhomboid muscles is superior?

Answer 16

Rhomboid minor

Question 17

What is the attachment of rhomboid major?

Answer 17

Originates from the spinous processes of T2-T5 vertebrae,

Attached to the medial border of the scapula (between scapula spine and inferior angle)

Question 18

What nerve innervates the rhomboid major?

Answer 18

Dorsal scapula nerve

Question 19

What is the action of the rhomboid major?

Answer 19

Retracts and rotates the scapula

Question 20

What are the attachments of rhomboid minor?

Answer 20

Originates from the spinous processes of C7-T1 vertebrae

Attaches to the medial border of the scapula (same level as spine of scapula)

Question 21

What nerve innervates the rhomboid minor muscle?

Answer 21

Doral scapula nerve

Question 22

What is the action of the rhomboid minor muscle?

Answer 22

Retracts and rotates the scapula

Question 23

What is the blood supply to the trapezius?

Answer 23

Transverse cervical artery

Question 24

What is the blood supply of the lattissimus dorsi?

Answer 24

Thoracodorsal artery

Question 25

What is the blood supply of the levator scapulae?

Answer 25

Transverse cervical artery and ascending cervical artery

Question 26

What is the blood supply to the rhomboid major and minor?

Answer 26

Dorsal scapular artery