most arm injuries can be prevented and most are. This run may seem like a lot of injuries but it always amazes me how the majority of pitchers don't need some type of surgery.
Most pitchers are in the training room constantly having something done. If they only pitched when everything felt good, we wouldn't play many games.
This is why when people make the comment that "how did they not know he was hurt", it's silly. This is why the handling of pitchers soreness and injuries is so difficult.
Overhand throwing just isn't a motion that our arm especially the shoulder is really designed to do.
although I do agree that much if the stress on the arm is early on, but we are getting better at it.