http://www.washingtonpost.com/wp-dyn...2003Oct10.html

Concussions, Impact Studied by the NFL

By Guy Gugliotta
Washington Post Staff Writer
Saturday, October 11, 2003; Page D03

Professional football players suffered nearly 900 concussions between 1996 and 2001, experiencing impacts equivalent to a head-on auto collision at up to 25 mph, according to a new study by the NFL.


Despite the prevalence of these injuries, the researchers found no evidence that any helmet manufacturer had ever systematically analyzed how concussions occurred or how to devise headgear to avoid them:

"Whenever a manufacturer would make a claim, I would always tell them there was no way they could know what their equipment could do," said internist Elliot Pellman, chairman of the NFL's Committee on Mild Traumatic Brain Injury. "This study has enabled us to gather information that we can hand over to the companies."

Pellman, who is also chairman of the medical department of the New York Jets, said in a telephone interview that he became concerned about concussions after Jets wide receiver Al Toon retired in 1992 because of lingering "post-concussion syndrome," a combination of effects that can include everything from headaches and dizziness to depression and personality change.

His concern was echoed by NFL Commissioner Paul Tagliabue, who ordered formation of the committee to conduct a prolonged and exhaustive analysis of concussions. The first installment of the committee's work appears in this month's issue of the journal Neurosurgery, and deals with the physics of concussion collisions.

"In the early 1990s, as we looked more deeply into the specific area of concussions, we realized that there were many more questions than answers," Tagliabue wrote in the journal. "We are confident that important new information will continue to advance the cause of improving the safety of professional and amateur athletes on all levels."

Pellman said subsequent issues of Neurosurgery would contain articles related to other aspects of concussions, including early and lingering effects and the question of whether concussions are more prevalent in pro football today than 30 or 20 years ago, or whether certain people are somehow predisposed to suffer from concussions, or simply worsen as they experience repeated blows.

Although the researchers had data from nearly 900 concussions, they focused in the study's first installment on the 182 concussions for which they had videotape. If they could view the incident from two angles or more, they were often able to recreate the collision using crash dummies.

What they found was all "brand-new information," Pellman said. In all cases the "struck player" was the only one injured. In 61 percent of the injuries, the player collided with the opponent's helmet or face mask, while 16 percent were hit by a shoulder or arm and another 16 percent suffered concussions when the backs of the heads struck the ground. The remainder were caused by collisions with another part of the opponent's body or were impossible to determine.

By using data from the crash dummy tests, the researchers found that the principal damage came from what they called "translational acceleration" imparted to the victim's head by the opponent.

Opponents slammed into an unaware player at impact speeds between 21 and 25 mph, the study said. The translational acceleration caused the concussed player's head to rebound at a speed of 16 to 20 mph. The striking player's head, by contrast, experienced a reduction in head velocity of only nine to 12 mph.

"No one realized that the impacts were that high," Pellman said. "It shows that today's helmets are doing a pretty good job, but we think we are going to redefine how this injury is looked at, and there's much more information to come."