Scapulohumeral (Intrinsic) Muscles

Question 1

Deltoid

Answer 1

Proximal: distal clavicle (anterior head), acromion (middle head), & spine of scapula (posterior head)
Distal: deltoid tuberosity
Innervation: axillary nerve (C5,C6)
Blood supply: deltoid branch of thoracoacromial artery
Functions: FLX/EXT, IR/ER, & ABD

Question 2

Teres Minor

Answer 2

Proximal: middle part of lateral border of scapula
Distal: inferior facet of greater tubercle of humerus
Innervation: axillary nerve (C5,C6)
Blood supply: circumflex scapular artery
Functions: ER & stabilizes humeral head

Question 3

Teres Major

Answer 3

Proximal: posterior surface of inferior angle of scapula
Distal: intertubercular groove (medial lip)
Innervation: lower subscapular nerve
Blood supply: circumflex scapular artery
Functions: IR/EXT/ADD

Question 4

Infraspinatus

Answer 4

Proximal: infraspinous fossa
Distal: greater tubercle of humerus (middle)
Innervation: suprascapular nerve (C5-C6)
Blood supply: suprascapular artery
Functions: ER & stabilize humeral head

Question 5

Supraspinatus

Answer 5

Proximal: supraspinous fossa
Distal: greater tubercle of humerus (anterior)
Innervation: suprascapular nerve (C5-C6)
Blood supply: suprascapular artery
Functions: ABD & stabilize humeral head

Question 6

Subscapularis

Answer 6

Proximal: subscapular fossa
Distal: lesser tubercle of humerus
Innervation: upper and lower subscapular nerve (C5-C6)
Blood supply: subscapular artery
Functions: ADD & IR