The Sports Legacy Institute held a press conference in advance of Sunday's Super Bowl to announce a new initiative calling for all state high school athletic associations to ban full-contact practices and games during the offseason. Current and former NFL players, including Ravens center Matt Birk, Titans quarterback Matt Hasselbeck and Chiefs Eric Winston were also present to show their support for the proposed ban.

Currently, 29 state high school athletic associations allow full-contact drills during the offseason, and none impose any in-season limits. In contrast, last year the NFL banned offseason full-contact drills and limited them to less than one drill per week during the season.

"The only reason it's not the same way in high school is that players cannot negotiate - they have no voice. We are here to lend our voice for these young men," said Titan quarterback Matt Hasselbeck.

Limiting offseason hits is just a small step, but the organization hopes it will be the impetus for larger high school football reform. "We urge coaches to voluntarily comply and parents to not enroll their children in programs that still allow offseason hitting," said Chris Nowinski, co-founder, along with Robert Cantu, of SLI.

The initiative is the latest step the Boston-based nonprofit SLI's attempt to reduce the risk of concussion and Chronic Traumatic Encephalopathy among athletes and other at-risk groups. Launched in 2012, SLI's Hit Count encourages organizations to track and limit the number of head hits suffered by an athlete, and more recently, SLI created its Concussion Checklist to help parents, coaches, and administrators assess the safety of their sports programs.

"The brain cannot be conditioned to receiving trauma. Hits to the head only creates risk of injury, therefore every opportunity should be sought to eliminate head trauma where we can," Cantu said.