Stefan Duma loves football. But when he’s at a game, you won’t find him cheering in the stands. Instead, he’s on the sidelines watching his computer screen. That’s because it displays the force of every hit to the head taken by each player.
Duma is a biomedical engineer at Virginia Tech, in Blacksburg, Virginia. He studies injuries caused by head-to-head collisions in contact sports such as football and hockey. Using sensors placed inside helmets, he has recorded more than 150,000 impacts endured by players ranging from 7-year-olds to the Virginia Tech Hokies football team. The data helps Duma understand what kinds of situations are most likely to cause concussions and other types of injuries—and how helmets can help prevent them.
Science World spoke with Duma about how he’s using this data to design safer, more effective helmets.
Why did you decide to study helmet technology and concussions in athletes?
I got a call from the Virginia Tech athletic department asking which helmets they should purchase, since no public data that measured helmet performance existed. That was eye-opening for me. There was no way to tell which helmets performed better than others. So we immediately began outfitting the football players with sensors.
How does a helmet protect an athlete?
The purpose of a helmet is to reduce head acceleration. A concussion occurs when a sudden impact, such as a head-to-head collision on the field, causes the head to accelerate very fast. As it accelerates, the brain stretches and deforms, causing a concussion. Using a variety of foam and padding technologies, helmets reduce head acceleration, although some work better than others. The better helmets reduce head injury, lowering your risk of a concussion.
How do the helmet sensors work?
Six accelerometers fit into the foam padding of the players’ helmets. The accelerometers measure head motion and catch every single head impact a player receives. They record the force in g, a unit for measuring acceleration.
Then a wireless transmitter sends the information in real time to a computer on the sidelines, where we watch the numbers. This way, we know exactly how many times players are hit, in what direction, and how hard.
Although every player is different, we know that 80g to 100g can often cause a concussion. If a player receives a blow in that range, the sensor sends an automatic alert to the team physician to see if the athlete needs a break.
How do you rate helmet effectiveness?
We transferred everything we learned on the field about helmet-to-helmet collisions into the lab. We tested each helmet on the market 120 times to see how well it reduces acceleration. Then we combined that data and developed star ratings for each helmet.
A helmet with a one-star rating protects players much less than a helmet with a five-star rating. This evaluation system has resulted in manufacturers designing better helmets. We started with football helmets but have recently begun testing hockey and baseball helmets.
What do you like most about your job?
I’ve always been a big football fan. Knowing what we know now about the risk of injury adds a different element to the game. But it feels good to know that the research we are doing may reduce the risk of concussions.