Question

1. Why are muscles that are associated with the shoulder girdle called into action during extreme ranges of motion of the shoulder joint?

   	a.	Muscles of the shoulder girdle are not involved with shoulder joint motion
   	b.	Their contraction protects the rotator cuff and prevents tears in the clavicular ligaments
   	c.	Their contraction moves the position of the glenoid fossa to facilitate humeral movement
   	d.	Their contraction moves the clavicle so its glenoid fossa remains in a position from which the humerus can move

Answer 1

Q.Why are muscles that are associated with the shoulder girdle called into action during extreme ranges of motion of the shoulder joint?

Answer:

d)Their contraction moves the clavicle so its glenoid fossa remains in a position from which the humerus can move

As shoulder joint goes through more extreme ranges of motion, scapular muscles contract to move shoulder girdle so that its glenoid fossa will be in a more appropriate position from which the humerus can move.

Shoulder girdle muscles contract to move shoulder girdle and to enhance movement of upper extremity when shoulder goes through extreme ranges of motion.