Rotator Cuff Muscles

Question 1

Supraspinatus

Answer 1

Origin -
Superior to spine of scapula

Insertion -
Greater tuberosity of humerus (superior)

Actions -
Abduction

Question 2

Infraspinatus

Answer 2

Origin -
Posterior surface below spine of scapula

Insertion -
Greater tuberosity of humerus (posterior)

Actions -
Horizontal extension of the shoulder
Lateral rotation of the shoulder
Stabilisation of the shoulder

Question 3

Subscapularis

Answer 3

Origin -
Anterior surface of scapular

Insertion -
Lesser tuberosity of humerus

Actions - 
Medial rotation of the shoulder
Adduction of the shoulder
Extension of the shoulder
Stabilisation of the shoulder

Question 4

Teres Minor

Answer 4

Origin -
Lateral border of the scapula

Insertion -
Greater tuberosity of humerus

Actions -
Lateral roatation
Stabilisation of the shoulder joint