Upper Limb Myology

Question 1

What muscles connect the upper limb to the spine?

Answer 1

• upper/middle/lower trapezius
• latissimus dorsi
• rhomboids
• levator scapula

Question 2

What are the attachment points of upper trapezius?

Answer 2

S: middle 1/3rd of the superior nuchal line, external occipital protuberance (inion) to the C7 SP via the nuchal ligament
Inferior/Lateral: lateral clavicle, acromion

Question 3

What are the actions of upper trapezius when the head/neck are fixed?

Answer 3

S-T elevation

S-T upward rotation

Question 4

What are the actions of upper trapezius when the scapula is fixed?

Answer 4

• head/neck extension (esp. when bilaterally contracting)
• head/neck ipsilateral lateral flxion
• head/neck contralateral rotation

Question 5

Which two muscles work together to cause upward rotation of the scapula?

Answer 5

• middle trapezius

- lower trapezius

Question 6

What are the attachment points of middle trapezius?

Answer 6

• medial: C7-T5 SPs

- lateral attachment: superior lip of the spine of the scapula

Question 7

What’s the action of middle trapezius?

Answer 7

S-T retraction

Question 8

What are the attachments points of lower trapezius?

Answer 8

• medial: T6-T12 SPs

- lateral: medial end of the spine of the scapula (root of spine)

Question 9

What are the actions of lower trapezius?

Answer 9

S-T depression

S-T upward rotation

Question 10

What’s the widest back muscle?

Answer 10

latissimus dorsi

Question 11

What are the attachment points of latissimus dorsi?

Answer 11

inferior/medial: SP T6 - iliac crest, lumbar and sacral vertebrae via the thoracolumbar fascia, ribs 9-12, inferior angle of the scapula (sometimes)
superior/lateral: floor of the bicipital groove

Question 12

What are the actions of latissimus dorsi?

Answer 12

G-H internal rotation
G-H extension
G-H adduction

Question 13

What are the attachment points of the rhomboids?

Answer 13

M: SP C7-T5
L: root of the spine of the scapula to the inferior angle of the scapula

Question 14

What are the actions of the rhomboids?

Answer 14

S-T retraction
S-T downward rotation
S-T elevation
Helps serratus anterior hold the scapula against the ribs

Question 15

What’s the fibre direction of the rhomboids?

Answer 15

inferolateral/superomedial

Question 16

What are the attachment points of levator scapula?

Answer 16

S: TVP C1-4
I: superior angle to the root of the spine of the scapula

Question 17

What are the actions of levator scapula when the head/neck are fixed?

Answer 17

S-T elevation

S-T downward rotation

Question 18

What are the actions of levator scapula when the scapula is fixed?

Answer 18

• head/neck extension (when bilaterally contracting)
• head/neck ipsilateral lateral flexion
• head/neck ipsilateral rotation

Question 19

What are the muscles of the pectoral region?

Answer 19

• pectoralis major
• pectoralis minor
• subclavius (but I don’t need to know this one yet)
• serratus anterior

Question 20

What are the two fibre divisions of pectoralis major?

Answer 20

upper fibres (clavicular head) and lower fibres (sternocostal head)

Question 21

What are the attachment points of pectoralis major?

Answer 21

• medial attachment (upper fibres): medial 1/2 of the anterior clavicle
• medial attachment (lower fibres): sternum, anterior costal cartilages of ribs 2-6
• lateral attachment (both heads): lateral lip of the bicipital groove

Question 22

What are the actions of pectoralis major?

Answer 22

• G-H medial rotation
• G-H adduction
• G-H horizontal adduction
• G-H flexion (from deep extension)
• G-H extension (from deep flexion)

Question 23

What are the attachment points of pectoralis minor

Answer 23

S: coracoid process
I: ribs 3-5

Question 24

What are the actions of pectoralis minor?

Answer 24

• S-T protraction
• S-T depression
• S-T downward rotation
• if the scapula is fixed, pectoralis minor helps to elevate the ribs with forced inhalation

Question 25

What's "tipping scapula"?

Answer 25

the inferior angle of the scapula moves posteriorly off the rib cage

Question 26

What are the attachment points of serratus anterior?

Answer 26

M: anterior surface of the medial border of the scapula L: lateral surfaces of the upper 8 ribs

Question 27

What are the actions of serratus anterior?

Answer 27

- S-T protraction - S-T upward rotation (lower fibres onlly) - keeps the medial border of the scapula flat against the ribs -- if this muscle is weak, a winging scapula can present

Question 28

What's the fibre direction of upper, mid and lower trapezius?

Answer 28

upper: inferolateral; superomedial mid: medial/lateral lower: superolateral; inferomedial

Question 29

What are the muscles of the pectoral region?

Answer 29

- pectoralis major - pectoralis mino - subclavius - serratus anterior

Question 30

What are the divisions of pectoralis major?

Answer 30

- upper fibres (clavicular head) | - lower fibres (sternocostal head)

Question 31

What are the attachments of pectoralis major?

Answer 31

- medial attachment (upper fibres): medial 1/2 of the anterior clavicle - medial attachment (lower fibres): sternum, anterior costal cartilages of ribs 2-6 - lateral attachment (both heads): lateral lip of the bicipital groove

Question 32

What are the actions of pectoralis major?

Answer 32

- G-H medial rotation - G-H adduction - G-H horizontal adduction - G-H flexion (from deep extension) - G-H extension (from deep flexion)

Question 33

What are the attachments and actions of pectoralis minor?

Answer 33

``` S: coracoi process I: ribs 3-5 action: S-T protraction action: S-T depression action: S-T downward rotation action: if the scapula is fixed, pectoralis minor helps to elevate the ribs with forced inhalation ```

Question 34

What are the attachments and actions of subclavius?

Answer 34

M: 1st rib and its costal cartilage L: middle 1/3rd of inferior surface of the clavicle action: anchors, depresses and draws the clavicle medially

Question 35

What are the attachments and actions of serratus anterior?

Answer 35

M: anterior surface of the medial border of the scapula L: lateral surfaces of the upper 8 ribs action: S-T protraction S-T upward rotation (lower fibres only) keeps medial border of the scapula flat against the ribs - if weak, winging scapula can present