Rotator Cuff Myology

Question 1

Subscapularis

Answer 1

Originates: medial 2/3 subscapular fossa
Adjacent fascia

Inserts: lesser tubercle of humerus

Medially rotates arm at shoulder
Upper/lower subscapular nerve C5,6,7

Question 2

Supraspinatus

Answer 2

Originates: medial 2/3 supraspinous fossa
Covering fascia

Inserts: upper facet of the greatert ubercle of humerus

Abducts arm at shoulder
Suprascapular nerve C5,6

Question 3

Infraspinatus

Answer 3

Originates: medial 2/3 infraspinous fossa/covering fascia

Inserts: middle facet of greater tubercle of humerus

Laterally rotates arm at shoulder
Supraspinous nerve C5,6

Question 4

Teres Minor

Answer 4

Originates: upper 2/3 lateral border of scapula

Inserts: lower facet of greater tubercle of humerus

Laterally rotates arm at shoulder
Axillary nerve C5,6

Question 5

Rotator cuff actions

Answer 5

Medial rotation: subscapularis
Lateral rotation: infraspinatus, Teres minor
Abduction: supraspinatus

Question 6

Rotator cuff innervations

Answer 6

Upper/lower subscapular nerve C5,6,7
Subscapular nerve C5,6: supraspinatus
Supraspinous nerve C5,6: infraspinatus
Axillary nerve C5,6: Teres minor