Untold lives and billions of dollars in sales, medical fees, and litigation costs could depend on a clear answer. If the relationship between the forces is strong, the key to reducing rotational acceleration is the same as reducing linear acceleration: Add more padding. Clearly helmet manufactures would prefer such a simple solution. If the connection is weak, however—or at least weak in the most dangerous hits—more padding will do little to reduce concussions, and companies will need to rethink current designs entirely, a very costly endeavor.
In 2003, a New Hampshire–based company named Simbex introduced a research tool called the Head Impact Telemetry System (HITS). Among other things, it seemed to have the potential to answer the question of correlation. HITS is an array of six spring-loaded accelerometers positioned inside a helmet to record the location and severity of significant impacts. After any hit over a certain threshold, the system beams the data to a companion device on the sidelines. Coaches can monitor players in real time, and researchers get reams of real-world data to dig through. Stefan Duma, the founding director of Virginia Tech’s Center for Injury Biomechanics, is among those working with HITS data; at his urging, every player on the university’s football team wears a HITS-equipped helmet. After analyzing data from two million impacts, Duma says there is a clear and strong connection between linear and rotational forces.
Unfortunately, other researchers say it’s not that simple. The correlation is high if you look at all hits, they say, but it falls apart when you look at highly angular ones—the hits that carry a greater risk of concussion. “Take an extreme example,” says Boston University’s Cantu. “If you impact the tip of the face mask, if you have another player coming at it sideways, you’re going to spin the head on the neck and have very low linear acceleration and very high rotational acceleration.”
Indeed, for every advocate of the HITS data, there exists an equally vocal critic. They say that helmets deform under the force of a 250-pound linebacker, skewing data. They say the HITS algorithm that calculates rotation is flawed. They point out that the founder of HITS is a co-author on all the published studies that validate the system. Blaine Hoshizaki, a biomechanics professor at the University of Ottawa whose research focuses on angular hits, sounds exasperated when I ask him about Duma’s findings. “You’ve got to look at the events that are really contributing to concussion,” he says. “It may be that in 1,000 hits, only 50 are highly non-centric, but maybe those 50 are the most dangerous—and that’s what our data shows.”
In essence, the system created to answer questions about concussions has raised a lot more questions. The resulting confusion sets off a cascade of effects. Unclear science makes for unclear standards, and unclear standards leave a lot of room for interpretation. The impact on the helmet industry is conspicuous: It’s become a free-for-all.
In December 2010, a longtime auto-racing safety equipment maker named Bill Simpson happened to attend one of the Colts games in which medics helped Austin Collie off the field after a concussion. Following the incident, Simpson asked the Colts’ offensive coordinator, a friend, what had happened to his receiver.
“Oh, that’s just part of the game,” the coach said.
Simpson saw an opportunity. In auto racing, he’s known as the Godfather of Safety, and once set himself on fire to demonstrate the efficacy of one of his racing suits. He figured he could make a better football helmet, so he got to work in his Indianapolis warehouse. By 2011, several pros, including Collie, were wearing early experimental versions of Simpson’s helmet.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.