Scapular & rotator cuff muscles

Question 1

Deltoid

Anterior, Lateral, Posterior

Answer 1

O: Lateral 1/3 of clavicle, acromion and spine of scapula
I: Deltoid tuberosity of the humerus bone
A: 1. Anterior fibers: Flexion &medial rotation of humerus
2. Lateral fibers: Abduction of humerus
3. Posterior fibers: Extension & lateral rotation of humerus
N: Axillary nerve

Question 2

Supraspinatus

Answer 2

O: Supraspinous fossa of scapula
I: Greater tubercle of the humerus bone
A: Assists deltoid muscle in abduction of humerus at the shoulder joint
N: Suprascapular nerve

Question 3

Infraspinatus

Answer 3

O: Infraspinous fossa of scapula
I: Greater turbercle of the humerus bone
A: Lateral rotation of humerus at shoulder joint
N: Suprascapular nerve

Question 4

Teres Minor

Answer 4

O: Inferior lateral border of scapula
I: Greater tubercle of the humerus bone
A: Lateral rotation of the humerus at the shoulder joint
N: Axillary nerve

Question 5

Teres Major

Answer 5

O: Inferior angle of scapula
I: Medial lip of intertubercular groove of the humerus bone
A: Extends & assists in adduction & medial rotation of the humerus at the shoulder joint
N: Lower subscapular nerve

Question 6

Subscapularis

Answer 6

O: Subscapular fossa of scapula
I: Lesser tubercle of the humerus bone
A: Medial rotation of the humerus at the shoulder joint
N: Upper & lower subscapular nerve

Question 7

What muscles form the rotator cuff?

Answer 7

Supraspinatus, Infraspinatus, Teres minor & Subscapularis

Question 8

What is the primary function of the rotator cuff muscles?

Answer 8

Hold the head of the humerus bone (secure) in the glenoid fossa of the scapula