Rotator cuff muscles: origins, insertions, nerves and actions
The rotator cuff is a group of four muscles that surround the shoulder joint and hold the head of the humerus in the shallow glenoid cavity of the scapula. The mnemonic SITS lists them: Supraspinatus, Infraspinatus, Teres minor and Subscapularis.
The table compares each muscle. Open a row to see the full page with a 3D model showing its attachments on the scapula and humerus.
| Muscle | Origin | Insertion | Innervation | Action |
|---|---|---|---|---|
| Supraspinatus | Supraspinous fossa of the scapula. | Superior facet of the greater tubercle of the humerus. | Suprascapular nerve (C5-C6). | Initiates abduction of the arm and stabilises the head of the humerus in the glenoid cavity. |
| Infraspinatus | Infraspinous fossa of the scapula. | Middle facet of the greater tubercle of the humerus. | Suprascapular nerve (C5-C6). | Laterally rotates the arm at the shoulder and stabilises the humeral head. |
| Teres minor | Upper two thirds of the dorsal surface of the lateral border of the scapula. | Inferior facet of the greater tubercle of the humerus. | Axillary nerve (C5-C6). | Laterally rotates the arm; weakly adducts; holds the humeral head in the glenoid cavity. |
| Subscapularis | Subscapular fossa on the costal surface of the scapula. | Lesser tubercle of the humerus. | Upper and lower subscapular nerves (C5-C7). | Medially rotates the arm; stabilises the humeral head anteriorly. |
Frequently asked questions
What does SITS stand for?
Supraspinatus, infraspinatus, teres minor and subscapularis, the four rotator cuff muscles.
Which rotator cuff muscle is most often torn?
The supraspinatus, because its tendon passes through the narrow subacromial space.
Which rotator cuff muscles laterally rotate the arm?
Infraspinatus and teres minor.
See each muscle in 3D
Last updated September 30, 2026. Educational use only. See our editorial policy.