Virginia Tech Helmet Lab takes on snow sports
Moguls. Aerials. Half-pipe. Big air. Skiing and snowboarding events send athletes soaring through the air and racing downhill at speeds creeping over 80 miles per hour.
These high-energy sports attract a rapt audience at the Winter Olympics every four years, but they’re also wildly popular among recreational athletes — the National Ski Areas Association reported 59 million visits to skiing or snowboarding areas in the U.S. during the 2020-21 season. But like any activity that combines high speeds and hard surfaces, snow sports come with a risk of getting hurt, and hundreds of thousands of skiing and snowboarding injuries occur annually. Head injuries account for 28 percent of those, and are the No. 1 cause of fatality in these sports.
That makes it critical to know which helmet provides the most effective buffer between the head and the ground for a skier who loses their balance or a snowboarder who doesn’t stick a landing. In time for peak ski season, the Virginia Tech Helmet Lab has added snow sports to the list covered by its nationally regarded five-star helmet rating system.
Out of 35 helmets the lab tested, two helmets merited all five stars, and eight earned four. The remainder earned three or fewer.
The ratings, which are built on years of Virginia Tech’s research and expertise in injury biomechanics, provide a unique, evidence-based way for consumers to know which helmets offer the best protection. They’re made possible by the lab’s rigorous analysis of what happens during a head impact in a particular sport, and which impacts are most likely to turn into injuries. The research is a collaboration with the Edward Via College of Osteopathic Medicine.
“The circumstances that lead to head injuries are unique for every sport,” explained Steve Rowson, an associate professor of biomedical engineering and mechanics and the Helmet Lab’s director. “What part of the head usually gets hit? At what angle? How fast? Understanding those conditions thoroughly enough to recreate them in the lab is the key to assessing how effective helmets will be in a way that’s relevant to what athletes experience in the real world.”
Rowson’s research group combed through videos of the men’s and women’s U.S. Ski and Snowboard Teams, analyzing any frame with a head impact. Mathematical analysis of the footage allowed them to extract the velocity, location, and angle of each hit.
That data informed the parameters of the drop tests the team ran back in the lab. A blue headform wearing one of the helmets plummeted down a vertical drop tower onto an angled anvil, whose slick steel surface stood in for a snow-covered hill. Sensors embedded in the headform recorded its acceleration at the moment of impact. Each helmet was tested multiple times at three impact locations and two impact angles, to cover the range of the most common crashes in the event footage.
These tests measured how much each helmet reduced the force of the impact. The researchers plugged those values into a customized risk function that calculated the corresponding reduction in injury risk, and categorized the resulting scores on a scale from one to five stars.
The lab’s rankings are the first to evaluate how effectively snow sports helmets protect athletes from brain injuries like concussion and how they perform relative to each other.
As with most sports, the existing safety regulations for this gear are based on a standard associated with lethal injuries like skull fractures. The pass-fail metric doesn’t capture differences between helmets or assess their performance against injuries like concussion, which occur at lower levels of force but are still potentially devastating.
More granular data on helmet efficacy could help address a puzzling mismatch between trends in helmet use and injury rates. Helmet use in skiing and snowboarding has been climbing steadily. Today, more than 80 percent of skiers and snowboarders wear helmets on the slopes, up from just 25 percent two decades ago. But while rates of catastrophic injuries have dropped, rates of other injuries, like concussion, haven’t. A rating system that judges helmet performance at a border range of forces could begin to move the needle on some of those other injuries.
The ratings can help in two ways, Rowson explained. The helmet ratings and the test procedures behind them are publicly available on the lab’s website, preventing injuries both by empowering consumers to choose the safest protective gear and by providing quantitative, reproducible tools to guide and motivate the design of better helmets.
“We’ve been rating helmets for a long time, and we’ve consistently seen enthusiasm not just from consumers and vendors but also from manufacturers,” he said. “Athletes want to wear the best head protection they can, and helmet companies want to produce the best equipment they can. The information contained in the ratings benefits everyone in this ecosystem and, we hope, can ultimately reduce the number of head injuries people experience in these sports.”
Snow sports are the lab’s seventh major ratings release. Rowson, along with Harry Wyatt Professor of Engineering Stefan Duma, published the first ratings for varsity football helmets in 2011. In the decade since, hockey, soccer, cycling, and youth football helmets have all been added to the portfolio. The lab’s research has also been instrumental in understanding the risks of drone flights over people. They’re currently working on developing ratings for equestrian helmets, baseball, softball, sensors, and other sports.
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