The NFL is turning to technology to both measure and mitigate pro football's effect on players' brains, pushing into unexplored territory as officials try to protect personnel from the violence of the sport.

But even as the league cracks down on helmet-to-helmet hits and subjects concussed players to more rigorous medical scrutiny, NFL officials and experts acknowledge they don't yet have the data they need to fully understand what causes concussions. If they can, with the help of technology, gain a greater understanding in that area, they hope that will help them better protect players against head injuries.

"We see impacts with an enormous amount of energy and the player is not concussed," said Richard Ellenbogen, co-chairman of the NFL's head, neck and spine committee. "And then we see a hit with less energy and the player is concussed. We have not been able to match the two. . . The goal is to see if we can correlate the impacts with the outcome in terms of concussion."

That goal will soon lead to placements of devices known as accelerometers in players' helmets to measure the force of hits to the head they absorb. The NFL committee plans to test three types of the devices - versions used in helmets, earpieces and mouthpieces - for possible use by players beginning next season.

After a particularly violent weekend of head-to-head collisions in October, the NFL announced it would strictly enforce its rules that prohibit some hits to the head and began issuing hefty fines to players who violated them. Increasingly concerned about the long-term effects of head trauma, the NFL last year modified its policies for the treatment of a player who suffers a concussion, prohibiting his return to a subsequent game or practice without clearance from an independent neurologist.

Measuring the force of blows to the head won't immediately lead to a concussion-prevention application, but Kevin Guskiewicz, a committee member and chairman of the department of exercise and sport science at the University of North Carolina, said the information-gathering nevertheless should begin as soon as possible.

"We are currently not where we'd like to be in understanding what an 80-G impact means relative to a 40-G impact. . . . My point has been all along if we don't start somewhere - like now - we'll never know," Guskiewicz said.

The data also could be used to teach players to better protect themselves, Guskiewicz said.

"One of the things I'm hopeful we can do - one of the things we do at UNC - is use the technologies, like the accelerometer, to help change behavior," Guskiewicz said.

"We sit down with players who are taking hit impacts and say, 'Look at what you're doing. You're lowering your head on certain types of hits.' I think technologies can be used in a preventive role as well."

Softer impact



The goal of prevention has spurred a wide range of experiments with new materials for helmets. For example, the Gladiator, eight years in development, incorporates a soft outer shell made of polyurethane foam, approximately a half-inch thick, over a hard shell helmet.

"It didn't make sense to put hard shells on the outside of helmets," said industrial designer Bert Strau, founder of Pennsylvania-based Protective Sports Equipment, which makes the Gladiator. "They don't have much give. We don't use hard bumpers [on vehicles] any more. They're soft."