Rotator Cuff

Rotator Cuff Muscles

The rotator cuff is a group of four muscles that stabilize the glenohumeral joint. Mnemonic: SITS

Clinical Note: Rotator cuff tears are common injuries, especially in overhead athletes and older adults. The supraspinatus tendon is most frequently affected.

The Four Muscles

1. Supraspinatus - Initiates abduction

   • Origin: Supraspinous fossa of scapula

   • Insertion: Greater tubercle of humerus (superior facet)

   • Nerve: Suprascapular nerve (C5-C6)

2. Infraspinatus - Lateral rotation

   • Origin: Infraspinous fossa of scapula

   • Insertion: Greater tubercle of humerus (middle facet)

   • Nerve: Suprascapular nerve (C5-C6)

3. Teres minor - Lateral rotation

   • Origin: Lateral border of scapula

   • Insertion: Greater tubercle of humerus (inferior facet)

   • Nerve: Axillary nerve (C5-C6)

4. Subscapularis - Medial rotation

   • Origin: Subscapular fossa

   • Insertion: Lesser tubercle of humerus

   • Nerve: Upper and lower subscapular nerves (C5-C6)

These muscles form a musculotendinous cuff around the shoulder joint, providing dynamic stability during movement.