Photo: Simbex

SHOCK ABSORBER: The inside of this helmet is outfitted with a wireless sensor system by Simbex.

Stefan Duma, a professor of mechanical engineering and director of Virginia Tech's Center for Injury Biomechanics, says getting even greater numbers of players outfitted with the device is important because there is “great potential for prevention of brain injuries, but the lack of scientifically sound, evidence-based studies is a barrier to improved prevention and treatment.” The data already collected have been enough to demonstrate that, contrary to conventional wisdom, most impacts that result in concussion occur on the side of the head rather than the front or the top. Riddell Sports Group, in Rosemont, Ill., which makes helmets for the NFL and dozens of college teams, has already responded with a new helmet design, called the RevolutionT, which extends farther down the jawline and includes the same kind of shock-absorbing padding near the jaw that is found in the helmet's crown. Previously, the only purpose for the padding on the side of its helmets was to improve the fit.

Asked if the NFL had any plans to use the HIT System or to make Riddell's new helmet a required part of every player's uniform, league spokesman Greg Aiello noted that each player gets to choose the type of helmet he wears. As for the monitoring system, Aiello says the league's Committee on Mild Traumatic Brain Injury (MTBI) is currently reviewing it but would offer no details regarding when the review would be completed or whether the group had reached any preliminary conclusions.

For its part, the NFL has been sponsoring studies aimed at quantifying on-field collisions using methods other than the HIT System. Chris Withnall, a senior engineer at Biokinetics and Associates, in Ottawa, conducted studies on behalf of the NFL that used video footage from games to reconstruct tackles using sensor-laden crash-test dummies [see “Anatomy of a Crash-Test Dummy,” elsewhere in this issue]. Withnall and his colleagues concluded that, on average, players diagnosed with concussions had their heads suddenly whipped in one direction, with acceleration greater than 80 g's. They found that blows below that threshold were much less likely to result in a brain injury.

Epidemiological studies suggest that there is a link between football-related concussions and subsequent memory problems and other brain dysfunction. But based on studies produced by its own MBTI committee, the NFL remains adamant that there is no such link and no proof that a player who has suffered a concussion is at much greater risk of subsequent brain injuries.

Informal evidence is cropping up, however, that contradicts the NFL's stance. Former NFL players who suffered multiple concussions during their playing days have begun reporting signs of memory loss, slurred speech, depression, and other signs of early-onset dementia. In November 2006, Andre Waters, a 44-year-old former Philadelphia Eagles player who suffered from depression, committed suicide. An autopsy revealed that his brain had deteriorated to an extent comparable to that of an 85-year-old with Alzheimer's disease. The pathologist who conducted the autopsy attributed the damage to repeated blows to the head over the course of the player's career.