Building a Safer Helmet
According to the Centers for Disease Control, traumatic brain injuries have been steadily increasing over the past decade. In recent years, the concern over concussions on the football field and in other sports has also been growing. And so, researchers at Purdue University have been working on building a better helmet that could possible provide more protection against traumatic brain injuries.
Taking a hit to the head could knock your lights out. But, researchers working in Purdue University's Neurotrauma Group say they have found a way to significantly decrease the energy delivered to the brain during these types of impacts.
Eric Nauman is an associate professor of mechanical engineering with an expertise in central nervous system and musculoskeletal trauma.
“Basically, the idea here, for most traditional helmets, is that you spread the force out over a larger area, and what that does is exactly what the NCAA was designed to do, it prevents skull fractures,” he said. “And when you prevent skull fractures, that’s good, that’s wonderful.”
The problem, says Nauman, is that while most helmets diffuse the force of the impact, they don’t really absorb much of the energy. That means the same force is still being transmitted to the skull, brain and neck.
It is that specific problem that has ignited a national debate about the links between football-related concussions and degenerative neurological diseases, like chronic traumatic encephalopathy, or CTE.
Dr. Julian Bailes is Chairman of the Department of Neurosurgery at NorthShore University HealthSystem.
“CTE characteristically has a latency period after they finish playing contact sports, and so it’s usually six to 12 years. And that’s when they begin to have sort of brain failure,” said Dr. Bailes. “Their personality changes, their business and personal and marriage relationships fail. They typically leave their family. They’re predisposed to drug and substance abuse, depression, perhaps dementia, and then their life kind of unravels."
Dr. Bailes has autopsied the brains of dozens of former NFL players, and is an expert in CTE. He says that helmets have done a good job of preventing skull fractures, hemorrhages inside the brain, and blood clots, but have been less effective when it comes to concussions and smaller hits.
“We know now, as we realize, there’s no concussion-proof helmet,” he said. “In fact, the bigger, heavier, more robust helmets these days, I think, encourage some players who are predisposed to really sticking their head in there and hitting helmet to helmet.”
Last year, the Purdue research team completed a two-year study following football players at Jefferson High School in Lafayette, Indiana. Helmet-sensor impact data from each player were compared with brain-imaging scans and cognitive tests performed before, during and after each season.
Over two seasons, six players sustained concussions, but 17 others showed brain changes even though they did not have concussions.
Lead researcher Tom Talavage, Co-Director of Purdue’s MRI Facility, says the most important implication of the findings is the suggestion that a concussion is not just the result of a single blow, but in fact the totality of smaller blows that take place over time.
“What it really tells us is that our view of head trauma, historically, has been very narrow,” he said.
“I think more than ever, we realize that it’s the smaller hits, the ones we call sub-concussive blows, that there’s an impact to the head or movement to the head, where it doesn’t rise to the level of a known or diagnosed concussion,” said Dr. Bailes. “And so, there have been studies that have shown that with no concussion symptoms, there still can be some detection of the brain not working right.”
For that reason, the Purdue team has focused on the helmet lining.
“What we’re trying to do is develop materials that not only spread the force out, but also absorb a lot of energy, and so that’s the direction that we’re going here,” said Nauman.
What they’ve developed is a spongy, silicon-based material called fractal foam padding, and it looks and feels very different from what’s currently used as helmet padding.
A simple drop test comparison, and you can see the difference the material could possibly make.
Nauman says their data indicates this new material can cut the G-forces acting on the head by 50 percent; something that could be a game-changer when it comes to helmet safety and the reduction of concussive damage.
“When you get hit with a regular helmet, you actually feel the pain because remember that padding doesn’t give, so the shock is pretty much delivered right to your skull, so you actually feel the pain on your skin, whereas with this thing, you’re banging on it, and… nothing,” said Talavage.
The Purdue research team is applying for certification of their helmet. The hope is to test it out with players to see if in fact the data in the lab translates to safety on the field.
Earlier this month, Illinois Rep. Carol Sente proposed a bill that would limit high school football teams to playing tackle during one practice per week. The restriction, she contends, could help reduce the number of hits athletes take to the head.