Which football helmets should I buy?
It’s what a Virginia Tech athletics equipment manager asked Stefan Duma, a faculty member at the university’s department of Biomedical Engineering and Mechanics, in 2009.
Duma’s team had been working to better understand what causes brain injury. It had placed sensors in Hokies players helmets. It had simulated car crashes.
The question seemed simple enough, until Duma and his colleagues delved deeper into it.
“We said, ‘We don’t know.’ We can buy helmets and test because there’s really no information available in what was good and what wasn’t,” says Steve Rowson, who, as a graduate student, joined this little-known football helmet project that was about to take off.
Duma’s group simulated hits with a guillotine-like device that plunged a dummy headform down cables onto an anvil.
“We bought the helmets, and we saw huge differences,’ Rowson tells USA TODAY Sports. ‘But we also felt like everyone should have that information, so we developed the Virginia Tech helmet ratings based on that. And it was like the first independent, objective way of evaluating helmets.”
The investigation that started in Duma’s basement lab sparked a wave of discussion that would define standards used by youth, high school and college teams and expand to other sports.
“It wasn’t like a pass/fail scale,” Rowson tells USA TODAY Sports. “It was, ‘Here are the best performers. Here are the next best. Here are the not so good performers,’ and that really resonated with consumers. It was a little disruptive to the football helmet manufacturing industry.”
Rowson is now director of Virginia Tech’s Helmet Lab that has reached national acclaim for its testing and studies. It published the first independent safety ratings for varsity football helmets in 2011 and continues to ramp up the standard for what constitutes a five-star helmet.
Just recently, it updated its rating system with new thresholds for those used in varsity and youth football and by bicyclists.
“The best helmets back in 2011 would be the very worst helmets today,” Rowson says.
Have you ever wondered about the force of a hit to the head your kid sees in practice and in games, and how their helmets are tested to protect from them?
Or how helmet recommendations are determined for various sports and age groups?
We spoke with Rowson about the history of his lab, the methods and evolution behind Virginia Tech’s STAR testing system and how it can help keep your athlete safe.
What is the Virginia Tech Helmet Lab and how does it replicate impact?
The lab is a collection of about 25 Virginia Tech faculty, staff, graduate and undergraduate students who study the forces that cause injuries all over the body and look for ways to prevent them from occurring.
They consider over a million head impacts to develop football readings. As they learn more, they add test conditions or change methods.
Sometimes, it’s a complete overhaul.
Their first varsity football helmet ratings were based on Duma’s drop test.
“We were only considering linear acceleration in the head, and it’s because there weren’t really good methods to evaluate rotation of the head,” Rowson says. “We didn’t know how rotational acceleration related to brain injury really well at the time, but we knew enough about linear acceleration that it had a correlation to concussion risk.
“However, a few years later, we had new data to tell us how rotational acceleration related to brain injury, and we upgraded the football method to include both linear and rotational acceleration. We have a pendulum impactor, which pretty much looks like a big upside down hammer that swings down and then it hits a dummy headform that has a helmet on it. Think of a crash test dummy. That dummy headform has sensors inside it.”
Helmet manufacturing has advanced, Rowson says, as the lab has.
“The amount of change that we’ve seen in helmet design over the last decade is probably more than we saw in the previous 30 years combined,” he says.
Understanding the impact and distribution of hits
I asked Rowson, who has a master’s and Ph. D in Biomedical Engineering from Virginia Tech, if he could come up with an analogy for the greatest impact a helmet sustains on a field. He did some math and got back to me with the following scenario:
Head accelerations associated with concussion are comparable in magnitude to those experienced in unbelted car crashes at approximately 17 mph for college-level players and 10 mph for youth-level players.
However, damage from concussions can be cumulative. The lab tests helmets with the hardest hits as well as what Rowson calls “everyday impact” players see on the field.
“They probably see that impact multiple times, and then, with our highest impact condition, not every player might see it,” he says. “The ones who do are at risk of injury. The helmet influences how much force is transferred to the head during all those impacts. So if a helmet’s too soft and too thin, it might not do great under higher impact energy or if it’s optimized for high energy hits, it might do poorly at the low energy hits. So we have a comprehensive evaluation of it where you can’t overdesign for really hard hit impacts or everyday impact.”
No helmet is concussion-proof, the lab states on its website, and any athlete can sustain a head injury. It identifies the helmets that best reduce your chances.
The Summation of Tests for the Analysis of Risk (STAR) score is calculated based on a helmet’s performance in a series of impact tests that are sports-specific. Tests are weighted based on how often people experience similar impacts.
The lower the score, the better the protection. Scores are assigned a number of stars between 1-5, with 5 stars being the best.
“Our ratings are representative of the average,” Rowson says. “There is gonna be some in that (data) distribution who get hurt at really low head accelerations, and there’s gonna be other people who don’t seem to ever get hurt, even at high head accelerations, and that comes down to biological variance. Everyone has their own tolerance to head impact, everyone’s material properties and their brain tissue’s different.
“So it’s kind of a predicted number of injuries for a given number of head impacts that we would expect to see on average, amongst a lot of people. We identify helmets that systematically reduce head acceleration and thus risk.”
What’s the difference between a four-and five star helmet? (Hint: They’re both good.)
Rowson says just about every varsity and youth football helmet they recently rated earned five stars.
“But that starts to dilute what a five star meaning is,” he says. “The five star rating is intended to identify what the very best available protection is. And if every helmet that’s being rated is five stars, it takes a little meaning away from that.”
The ratings update rescales those areas to make the five-star winners truly standout performers. The new thresholds reduced the number of five-star helmets from 167 to 38 (bicycle), 33 to 11 (varsity football) and youth football (26 to 6).
The lab still recommends any four or five star helmets.
“It’s not just like everything got good,” Rowson says, “it’s they got good, but to different extents where we could identify meaningful differences.”
Watch contact in practice: Understanding helmet differences and unique risks
According to Virginia Tech, varsity football helmets used to have corresponding youth versions, but there were often few differences between them. There was little data describing how risk differed for youth players.
Today, the lab model for “youth” football simulates a 10-to-12-year-old boy, the varsity model an 18-to-24 year old male.
“A kid isn’t necessarily just a scaled down adult,” Rowson says. “Their head is bigger relative (to) their body than we see in a full grown male, their brain’s still developing, and there’s differences in kind of how they respond to a head impact.
“Every impact scenario we recreate in a lab is weighted based on how often a player is gonna see (it) on the field. So like kids, when they fall to the ground, they have a heavier head and a weaker neck, and the helmet’s pretty heavy relative to their body mass compared to an adult. So their helmet’s more likely to follow through and strike the ground. So we see more side and back impacts in youth football than we do in varsity football.”
As part of a groundbreaking 2012 study funded by the National Highway Traffic Safety Administration, Virginia Tech researchers put sensors inside the helmets of seven players aged 7–8 years old for a season and measured their impacts.
They found that 76% of the ones greater than 40 g (40 times the acceleration of gravity) and 100% of impacts greater than 80 g occurred during practices.
‘It was first data measuring head impacts in youth football players,’ Rowson says.
Following the study, Pop Warner youth football outlawed drills that involved full-speed, head-on-blocking and tackling that starts with players lined up more than three yards apart, as well as head-to-head contact.
According to The New York Times, Pop Warner officials said they were persuaded by data from the youth study that indicated the level of severity of some hits were similar to some of the more severe impacts college players experience.
“We’re like, ‘Wow, all our hardest hit impacts are coming from this one (Oklahoma) drill,’ ” Rowson says. “And out of all the games we collected, we didn’t see that kind of impact happen a single time. We’re like, ‘We don’t think you should be doing this,’ and the coach was really receptive. It was just a local youth football team, and it was a dad coaching who had that drill in there, because that’s what he did when he was a kid.”
A follow-up study of football teams comprised of players aged 9–12 suggested head impact exposure could reduce significantly by limiting contact in practices to levels below those experienced in games.
Coach Steve: Why are boys sports declining? Former NBA star looks for solutions
How helmet ratings differ by sport
Their helmet research always starts in the real world, Rowson likes to say. They learn how people are getting hurt and they match those conditions – the speed at which they’re hitting their head, where they’re hitting their head, their acceleration profile – in the lab.
With cycling, the researchers look at a fraction of the head impacts as football.
They don’t put a sensor on everyone because cycling is an individual sport and crashes are rare. Instead, Rowson says, they identify riders involved in crashes and collect their helmets.
They buy the same helmet and start hitting it until they match the damage profile, then back calculate the location and velocity at which they hit their head.
For snow sport, researchers have traveled to big events on mountains and set up cameras from various angles.
Through video tracking, they calculated their head impact speed into the ground.
The lab now has helmet ratings for varsity football, youth football, flag football, hockey, bicycle, equestrian, soccer, snow sport and whitewater.
They’ll be announcing rating programs for baseball and softball soon.
“Essentially, we’re trying to cover all sports,” Rowson says. “The ultimate goal is for us to be able to provide data to everyone on what’s available.”
The lab doesn’t formally advise any leagues, but often, the leagues come to them. A full time faculty member is assigned to direct outreach, host tours, run STEM activities for kids and answer questions.
The questions, it seems, come every day.
“Sometimes they’re very technical, sometimes they’re more general: What does this mean and how do we use it?” Rowson says.
We know now from Duma, the Virginia Tech professor of engineering whom its football team sought out in 2009, how a seemingly innocent one can lead to a scientific explosion.
Steve Borelli, aka Coach Steve, has been an editor and writer with USA TODAY since 1999. He spent 10 years coaching his two sons’ baseball and basketball teams. He and his wife, Colleen, are now sports parents for two high schoolers. His column is posted weekly. For his past columns, click here.