The crunch as a player tackles another is a common sound in football, but it can have negative consequences.
And the Michigan High School Athletic Association is working to keep this contact safer.
"What we can do is if a parent knows that their child is going to be playing a sport we can do baseline testing and we can tell if they are not normal" says Judy Goik with McLaren Bay Region Rehab.
New policies for 2014 say only 2 contact practices per week are allowed so players receive the smallest amount of time literally impacting each other.
But today athletes stretched out their muscles and with a full sport focused physical, athletes like Zachary Fylling got the rundown on what they need to do to be fighting fit.
"I like coming to sports physicals better than just going to a regular physician. I feel like it's a better evaluation of how your body really is" says Zachary.
Injuries can include everything from minor sprains to broken bones and concussions.
So todays exams help athletes know where they need to work to protect themselves in the future.
"You need to stretch or work out those areas to become more flexible and that alone will improve your flexibility in your sport" says Zachary.
To see the full policy changes for the 2014 year by the MHSAA click the link HERE.