I think a lot of training camp injuries come from people not adequately training in the off season for the type of things they're going to be doing in training camp. Putting on a bunch of muscle in the weight room (or in the laboratory...) in the off season can be a detriment when you actually hit the field, as you might make too explosive of a move in one direction, and it causes a tear or rip. Particularly if that athlete hasn't been spending an adequate amount of time stretching or practicing actual movements they're going to be doing on the field.