Muscles of Rotator Cuff

Question 1

Supraspinatus

Answer 1

Attachments: supraspinous fossa of scapula and the deep fascia that covers muscle, superior facet of greater tubercle of humerus

Action: initiation of abduction of arm to 15 degrees

Innervation: Suprascapular nerve (C5, C6)

Blood supply: Suprascapular artery

Question 2

Infraspinatus

Answer 2

Attachments: infraspinatus fossa of scapula and the deep fascia that covers muscle, middle facet of greater tubercle of humerus

Action: lateral rotation of arm at glenohumeral joint

Innervation: Suprascapular nerve (C5, C6)

Blood supply: Suprascapular artery

Question 3

Teres Minor

Answer 3

Attachments: upper 2/3 posterior surface of lateral border of scapula, inferior facet on posterior surface of greater tubercle of humerus

Action: lateral rotation of arm at glenohumeral joint

Innervation: axillary nerve
Blood supply: Subscapular and circumflex scapular arteries, posterior humeral circumflex artery

Question 4

Subscapularis

Answer 4

Subscapularis

Attachments: subscapular fossa, lesser tubercle of humerus

Action: medial rotation of arm at glenohumeral joint
helps hold humeral head in glenoid cavity
• Stabilization of shoulder important action in all rotator cuff muscles!

Innervation: Upper and lower subscapular nerves (C5, C6, C7)

Blood supply: subscapular artery, lateral thoracic artery