Upper Limb Myology Flashcards
What muscles connect the upper limb to the spine?
- upper/middle/lower trapezius
- latissimus dorsi
- rhomboids
- levator scapula
What are the attachment points of upper trapezius?
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
What are the actions of upper trapezius when the head/neck are fixed?
S-T elevation
S-T upward rotation
What are the actions of upper trapezius when the scapula is fixed?
- head/neck extension (esp. when bilaterally contracting)
- head/neck ipsilateral lateral flxion
- head/neck contralateral rotation
Which two muscles work together to cause upward rotation of the scapula?
- middle trapezius
- lower trapezius
What are the attachment points of middle trapezius?
- medial: C7-T5 SPs
- lateral attachment: superior lip of the spine of the scapula
What’s the action of middle trapezius?
S-T retraction
What are the attachments points of lower trapezius?
- medial: T6-T12 SPs
- lateral: medial end of the spine of the scapula (root of spine)
What are the actions of lower trapezius?
S-T depression
S-T upward rotation
What’s the widest back muscle?
latissimus dorsi
What are the attachment points of latissimus dorsi?
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
What are the actions of latissimus dorsi?
G-H internal rotation
G-H extension
G-H adduction
What are the attachment points of the rhomboids?
M: SP C7-T5
L: root of the spine of the scapula to the inferior angle of the scapula
What are the actions of the rhomboids?
S-T retraction
S-T downward rotation
S-T elevation
Helps serratus anterior hold the scapula against the ribs
What’s the fibre direction of the rhomboids?
inferolateral/superomedial
What are the attachment points of levator scapula?
S: TVP C1-4
I: superior angle to the root of the spine of the scapula
What are the actions of levator scapula when the head/neck are fixed?
S-T elevation
S-T downward rotation
What are the actions of levator scapula when the scapula is fixed?
- head/neck extension (when bilaterally contracting)
- head/neck ipsilateral lateral flexion
- head/neck ipsilateral rotation
What are the muscles of the pectoral region?
- pectoralis major
- pectoralis minor
- subclavius (but I don’t need to know this one yet)
- serratus anterior
What are the two fibre divisions of pectoralis major?
upper fibres (clavicular head) and lower fibres (sternocostal head)
What are the attachment points of pectoralis major?
- 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
What are the actions of pectoralis major?
- G-H medial rotation
- G-H adduction
- G-H horizontal adduction
- G-H flexion (from deep extension)
- G-H extension (from deep flexion)
What are the attachment points of pectoralis minor
S: coracoid process
I: ribs 3-5
What are the actions of pectoralis minor?
- 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
What’s “tipping scapula”?
the inferior angle of the scapula moves posteriorly off the rib cage
What are the attachment points of serratus anterior?
M: anterior surface of the medial border of the scapula
L: lateral surfaces of the upper 8 ribs
What are the actions of serratus anterior?
- 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
What’s the fibre direction of upper, mid and lower trapezius?
upper: inferolateral; superomedial
mid: medial/lateral
lower: superolateral; inferomedial
What are the muscles of the pectoral region?
- pectoralis major
- pectoralis mino
- subclavius
- serratus anterior
What are the divisions of pectoralis major?
- upper fibres (clavicular head)
- lower fibres (sternocostal head)
What are the attachments of pectoralis major?
- 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
What are the actions of pectoralis major?
- G-H medial rotation
- G-H adduction
- G-H horizontal adduction
- G-H flexion (from deep extension)
- G-H extension (from deep flexion)
What are the attachments and actions of pectoralis minor?
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
What are the attachments and actions of subclavius?
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
What are the attachments and actions of serratus anterior?
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
