Head injury research is changing youth football by redefining what's seen as safe. Pop Warner, the premier recreation league for youngsters, now limits contact during coaching workouts. Full-speed, head-on blocking practice is forbidden, tackling drills by players standing more than three yards apart also are out and at least two-thirds of practice time must be non-contact. Supporters include University of Alabama coach Nick Saban. "We've got to get young people to play the game in a safe way," he told ESPN. "You've got to start somewhere, right?"

The rules announced last week are based on studies of football's link to concussions and other brain injuries, and also follow lawsuits against the National Football League. More than 2,000 retired players accuse the NFL of not protecting them against predictable harm. Research shows that damage from concussions can increase over time and that younger athletes' brains may be particularly vulnerable. Until recently, it was common to hide or minimize concussions -- even in school sports.

Pop Warner is the first national league at any level of football to restrict contact. With more than 285,000 players aged 5-15, it's America's largest and oldest youth football group -- a feeder system for high school, college and professional teams. Changes kick in when practice begins in August -- first with 10 hours a week and then six hours after Labor Day. National leaders await additional research before issuing even more restrictive rules to cover games. In any case, the organization feels that outlawing all contact and going to a flag-football format would send nearly all players elsewhere. "We can't wrap them in bubble wrap," says executive director Jon Butler. "It just doesn’t work that way."

Pop Warner leader says: "Hopefully, this will be looked back upon as a common-sense approach. If new research comes out, we will continue to change our rules to keep our kids as safe as we can." -- Jon Butler, executive director

Doctor says: "Research shows that more concussions occur in practice than during games. The impact of head-to-head contact causes the most severe concussions." -- Dr. Julian Bailes, chairman of Pop Warner’s medical advisory board

Father says: "I don't know if it's enough changes right now. That's probably something I will find out when practice starts. It might not be enough, because it's hard to monitor every coach to make sure that they're doing that in practice." -- Edward Marshall, dad with three sons and co-founder of the Central Oklahoma Pop Warner League