Rotator cuff muscles
| Muscle | Action | Origin | Insertion | Innervation |
|---|---|---|---|---|
| Supraspinatus | Abduction | Supraspinous fossa of scapula | Greater tubercle of humerus | Suprascapular nerve C5-6 |
| Infraspinatus | Lateral rotation | Infraspinous fossa of scapula | Greater tubercle of humerus | Suprascapular nerve C5-6 |
| Teres minor | Lateral rotation | Posterolateral surface of scapula | Greater tubercle of humerus | Axillary nerve |
| Subscapularis | Medial rotation | Subscapular fossa | Lesser tubercle of humerus | Upper and lower subscapular nerves |
misc notes
- lower subscapular nerve also supplies Teres major
- supraspinatus tendon poor blood supply
special tests
| Muscle | Test |
|---|---|
| Supraspinatus | Empty Can Test |
| Infraspinatus | External rotation of humerus |
| Teres minor | Hornblower's Test (?!) "Position the patient with the arm elevated to 90 degrees in the scapular plane and the elbow flexed to 90 degrees. Ask the patient to laterally rotate the arm against resistance. Test is positive if patient has pain or weakness." |
| Subscapularis | Lift-off test |