Actions of Scapular muscles

Question 1

What are the 3 actions of the Deltoid

Answer 1

1. Anterior portion Flexes and medially rotates the humerus
2. Middle portion abducts the humerus
3. extends and laterally rotates the humerus

Question 2

Which muscle stabilzes the Glenohumeral joint, but is NOT a rotator cuff muscle?

Answer 2

Teres Major

Question 3

What does the Supraspinatus do? (3 functions)

Answer 3

1. Initiate abduction of the humerus
2. laterally rotates the humerus
   3 stabilize the GH joint

Question 4

What are the functions of the Infraspinatus (2)?

Answer 4

Laterally rotates the humerus and stabilizes the GH joint

Question 5

What are the functions of the Teres Minor (2)?

Answer 5

Laterally rotates the humerus and stabilizes the GH joint

Question 6

What does the subscapularis do (2)?

Answer 6

Medially rotates the humerus and stabilizes the GH joint

Question 7

Which three muscles laterally rotate the humerus and stabilize the GH joint?

Answer 7

Supraspinatus, Inraspinatus and Teres Minor

Question 8

Which muscles have an opposing effect to that of the Infraspinatus?

Answer 8

The Teres major and subscapularis (medial rotation vs. lateral rotation). also opposing to Infraspinatus and Supraspinatus

Question 9

What does the Teres Major do?

Answer 9

Adduction and medial rotation of the humerus and stabilizes the GH joint (non rotator cuff)