Are you suggesting injuries to different players are somehow related? Or this is cause and effect? I got injured because you got injured?
Care to explain that logic?
Sometimes the injuries are just bad luck, sometimes and most likely in the case of Long it's just that his body can't take the rigors of the NFL anymore.
However, I feel that teams do need to do studies to constantly try and determine if they are doing something that induces more injuries. Things like: Is there unevenness to the practice field that catches guys out? Was there a change in the training staff and the methods and/or timing not giving guys enough time to recover? I believe the Bears changed the time when they were practicing once to avoid the heat of the day as they determined that could lead to hydration issues which could turn into muscle strains. For that matter, and I could be completely misremembering this, didn't Fox change the training staff and then there was a rash of injuries?
I don't doubt that teams look into all that, but at the same time, it would be interesting to know how often it gets re-evaluated and what sort of studies they have done.