Cantu, the co-director of the Center for the Study of Traumatic Encephalopathy at the Boston University School of Medicine, would like to see tackle football banned for athletes under the age of 14. In addition, he calls for no heading in soccer and no full-body checking in ice hockey at the same age.
"We're not calling for sports to not be played, but to be played with those restrictions," he said. "In the case of tackle football, substitute flag for tackle."
A young person's head, Cantu said, is too vulnerable and no modernized helmet or altered playing rules can fully prevent concussion.
"The youth brain housed in disproportionately big head on a very weak neck, it's a bobblehead doll-effect that increases the injury," said Cantu, who co-authored the recent book, "Concussions and Our Kids."
When Goodell was finished watching the players in Centreville a couple weeks ago, he headed toward the bleachers where parents were armed with questions.
The commissioner knows the challenges — safety concerns and increased interest in other sports, he says, but also the weak economy and the costs associated with football. He urged the parents to ask him anything.
A father wondered how long until the safe tackling program impacts the NFL. "Most of the time, changes in techniques happen from the top-down," Goodell said. "In this case, we believe implementing these techniques and learning these fundamentals at this age are going to help these kids all the way through."
To a mother whose 11-year-old son suffered a concussion the week before: "If any of your children are hurt, whether it's your leg or your head, make sure they're not afraid to raise their hand. That's all, and say, 'I don't feel right.' "