"What have I done?" Youngblood said. "I have to ask that question. You just don't know. We haven't defined it completely yet. That's one of the issues we're talking about here today."
Youngblood spoke Tuesday during a break from the first meeting of the Mackey-White Traumatic Brain Injury Committee. The group was formed by the NFL Players Association and includes professional athletes, past and current NFL players, doctors and researchers.
The committee wants to open a dialogue on brain injuries in professional football, discuss the latest research and begin developing recommendations to keep players safer.
"It's something very close to my heart," Youngblood said. "I became much more aware of it as I was inducted into the Pro Football Hall of Fame and got to know John Mackey more than just a guy at a cocktail party, and to see how ravaging brain injury and brain trauma can be."
Congress recently questioned NFL players and doctors about football head injuries. NFL Commissioner Roger Goodell testified in October about his league's concussion policies.
Since then, the league has instituted stricter return-to-play guidelines for players showing concussion symptoms, required each team to enlist an independent neurologist as an adviser, entered into a partnership with Boston University brain researchers who have been critical of the NFL's stance on concussions and conducted tests on helmets.
"You can never take the collision aspect out of the game," Youngblood said. "There's just no way, and in fact, that's something we kind of enjoy."
Dr. Thom Mayer, medical director of the NFL players' union, is serving as the committee co-chair, along with Arizona Cardinals wide receiver Sean Morey.
"This committee will serve as a 'superconductor' of information in order to drive rapid and meaningful progress in concussions," Mayer said. "We have assembled a world-class group of scientists to facilitate our work, which will benefit not only NFL players, but all those involved in all contact sports."
Chris Nowinski, a former college football player and professional wrestler, knew something was wrong after his sixth concussion -- at least that's how many he could remember.
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"I was blacking out in the ring and never was educated enough to know that was a problem," he said. "That led to ongoing memory problems and headaches. ... I wasn't getting better."
After three years of wrestling, Nowinski retired and began learning more about head injuries in professional sports. He's now president of the Sports Legacy Institute and co-director of the Center for the Study of Traumatic Encephalopathy at Boston University. He's also serving on the Mackey-White committee.
"We're just getting everyone's opinions to what we should be doing and how we should do it," Nowinski said.
Nowinski also has been soliciting athletes to donate their brains to research after their deaths, which will be studied at Boston University. He said 250 professional and amateur athletes have agreed, including 60 retired NFL players and four actives ones.
"The message is really giving back to the game," Nowinski said, "giving back to your former teammates."
Copyright 2010 by The Associated Press