What are the advantages of the shoulder joint being the most freely moving joint in the body?

For this discussion board post, you must write a thoughtful answer to TWO (2) of the following questions (minimum 150 words each; please clearly label which question you are answering).  Further, you must post to at least TWO (2) other students with genuine, thought provoking responses (minimum 100 words each).  

  1.  Why are diarthroses found predominantly in the limbs, while synarthroses and
amphiarthroses are found largely in the axial skeleton?

  2.  What are the advantages of the shoulder joint being the most freely moving joint in the body?

  3.  Cortisone shots can readily reduce swelling that occurs in joints, such as the shoulder and knee, following athletic injuries. Why is it dangerous for athletes to continue getting
these shots?

  4.  Physical therapists suggest various stretching exercises before proceeding with rigorous physical activity. Of what value are these exercises for the joint areas?

  5.  What does it mean to be “double-jointed”?

  6.  Most people can “crack” their knuckles. What does this term mean and what effect, if any, will this have on the knuckles in the future?

  7.  Bones appear to have numerous projections and protuberances. What do you suppose these are for?