3.5- shoulder muscles

covers muscles of shoulder not arm

rotator cuff muscles functions

stabilising the joint during movement and rotating arm

what are the rotator cuff muscles?

supraspinatus, infraspinatus, teres minor, subscapularis

trapezius muscle function

moving shoulder blade

trapeziums origin and insertion- descending

superior nuchal line/ occipital protuberance → lateral 1/3 of clavicle

trapeziums origin and insertion- transverse

spinous process C7-T3 vertebrae → acromion

trapeziums origin and insertion- ascending

spinous process T4- T12 vertebrae → spine of scapula

trapezius innervation

accessory nerve XI

trapezius blood supply

transverse cervical and posterior intercostal arteries

trapezius actions scapula

elevates, retracts, rotates, depress

pectorals major origin- clavicular

sternal half of clavicle

pectorals major origin- sternal

anterior surface of stermum

pectorals major origin- abdominal

aponeurosis of external abdominal oblique muscles

pectorals major insertion attachment

lateral lip of inter tubercular sulcus of humerus

pectorals major innervation

medial and lateral pectoral nerves

pectoralis major blood supply

pectoral branch of thoracoaromial artery

pectoralis major actions of arm

flexes, adductions, medially rotates

pectoralis minor origin and insertion

external surface offer rib 3-5 → coracoid process of scapula

pectoralis minor innervation

medial and lateral pectoral nerves

pectoralis minor blood supply

pectoral branch, superior/ lateral thoracic arteries

pectoralis minor actions

lowers lateral angle of scapula and protracts scapula

subclavius muscle origin and insertion

upper border of 1st rib/ costal cartilage → inferior surface of middle 1/3 of clavicle

subclavius innervation

subclavian nerve

subcalvius blood supply

clavicular branch of thoracoacrominal artery

subclavius action

anchors and depresses clavicle

subscapularis muscle origin and insertion

sub scapular fossa → lesser tubercle of humerus

subscapularis innervation

upper/lower sub scapular nerves

subscapularis blood supply

sub scapular and lateral thoracic arteries

subscapularis actions

medially rotates and adduction arms, helps hold humeral head in glenoid fossa

serrates anterior origin and insertion

lateral surfaces of ribs 1-9 → costal surface of medial boarder of scapula

serrates anterior innervation

long thoracic nerve

serrates anterior blood supply

lateral thoracic artery

serrates anterior actions

protracts and rotates scapula and holds it against thoracic wall

levator scapulae origin and insertion

transverse processes of axis and atlas/ posterior tubercles of C3-C4 vertebrae → medial border of scapula

levator scapulae innervation

anterior rami of C3-C4 spinal nerves, dorsal scapular nerve

levator scapulae blood supply

dorsal scapular/ transverse/ ascending cortical arteries

levator scapulae action

elevates scapular medially, inferiorly and rotates glenoid fossa

Supraspinatus origin and insertion

supraspinous fossa of scapula/ supreaspinatus fascia → greater tubercle of humerus

supraspinatus innervation

suprascapular nerve

supraspinatus blood supply

suprascapular artery

supraspinatus action

imitates arm abduction

Infraspinatus origin and insertion

infraspinous fossa of scapula/ infraspinatus fascia → greater tubercle of humerus

infraspinatus innervation

suprascapular nerve

infraspinatus blood supply

suprascapular artery

infraspinatus action

lateral rotation of arm