WASHINGTON, D.C.—Football has always been a violent sport. In the 1950s, when hard, polycarbonate shells replaced leather football helmets, the number of game-related fatalities plummeted. But hundreds of thousands of football-related concussions still occur every year. Now, one researcher is trying to harness the repulsive forces of magnets to reduce the impact of head-to-head collisions before they occur.
The idea is far from ready for the football field. It’s being tested in the lab, using machines for now. But one helmet expert says the strategy is worth pursuing given the seriousness of the problem.
The average NFL player takes more than 600 helmet hits a season, ranging from 20 g’s of force to more than 150. (For reference, your average roller coaster ride tops out at 5 g’s.) It typically takes about 100 g’s to cause a concussion. Standard, hard-shelled helmets keep the skull intact, but they can’t necessarily prevent concussions, because the brain essentially floats in a bath of cerebrospinal fluid. The fluid absorbs the impact of light blows, but big hits can send the brain ricocheting off the walls of the skull, damaging cells throughout the brain. The effects can be immediate—wooziness and light sensitivity for weeks, for example—and long-term; too many concussions can lead to a degenerative brain disease called chronic traumatic encephalopathy (CTE) later in life. In fact, CTE has been found in 96% of former NFL players examined posthumously.
One year ago, avid football fan Raymond Colello watched Wes Welker, a wide receiver for the Denver Broncos, go down with the second game-ending concussion of his career. “I began lamenting the fact that concussions may ultimately destroy football itself,” said Colello, a neuroscientist at Virginia Commonwealth University in Richmond, at a session here on Saturday at the Society for Neuroscience’s annual conference. “And at that point, like all people watching football on Sunday, I went out to my refrigerator for another beer.”
Staring at the magnets decorating the refrigerator door, he had an idea: What if you put such objects inside helmets? “You need some kind of force field around these guys,” he recalls thinking. “Maybe a repulsive force would possibly work.”
Roughly 60% of concussions in football are caused by head-to-head collisions. The material now packed inside traditional helmets reduces concussions by deflecting some of the energy after a collision occurs. According to Colello, magnets could extend the impact zone beyond the hard shell of players’ helmets, slowing the collision down before it occurs, thus reducing the overall g-force that a player experiences—just like brakes on a car. If a driver slams on the brakes just before it smashes into a wall, the impact will still occur, but at a slower speed, decreasing the g-forces that the driver experiences.
Colello wants to add palm-sized magnet inserts, made from the rare earth element neodymium, into the front and sides of helmets. The removable inserts follow the curvature of the helmet, so players can’t accidentally hit the field with the wrong pole facing outwards. According to Colello, they could increase the price per helmet by as little as $100.
Neodymium magnets are lightweight, but they still have a repulsive force-to-weight ratio of 300-to-1; a 1-pound (0.45-kilogram) magnet could repel at least 300 pounds (136 kilograms) of force. Colello’s magnet inserts would weigh in at half to three-quarters of a pound each. He tested the magnets with a standard drop test—the same test helmet manufacturers use to evaluate helmet strength. He attached the magnets to 10-pound (4.5-kilogram) weights, dropped one weight from various heights, and measured the g-force at the site of impact with the second, stationary weight.
Colello found that the magnets could reduce 140-g hits down to 88 g’s—a full 8 g’s lower than standard helmets—and 40 g’s down to a mere 3. The reduction of collisions with low g-forces is just as important, he says, given that repeated subconcussive hits can add up over time and lower the threshold for a concussion, until a relatively mild blow is enough to cause a disproportionate amount of damage.
The standard drop test is a good approximation of linear forces, or direct hits, but out on the field most hits are not head-on. Indirect hits produce rotational forces that send the brain twisting inside the skull, which can cause even more damage. “We really have to look at both linear forces, or direct hits, as well as rotational forces,” Colello said after the presentation.
To do that, he plans to send two Humanetics Hybrid II headforms (read: crash test dummies) equipped with magnetized helmets and accelerometers, careening down a zip line toward each other. By monitoring what happens when the crash-test dummies meet, Colello can be sure that the magnets aren’t just replacing linear forces with rotational ones. “We don’t want to trade concussions with spinal cord injuries,” he says.
The magnets would complement, rather than replace, current force reduction technologies in helmets, according to Colello, who plans to begin the zip line tests by the end of the year, and if the data prevail, proceed to human testing in just 6 months.
“The best helmets now are about as good as they are going to get,” says Stefan Duma, a biomedical engineer at Virginia Polytechnic Institute and State University in Blacksburg. “In order to make any big advancements we’re going to need outside-the-box thinking. [Colello’s] technology, in theory, extends the impact outside the helmet. It gives you a longer duration [of impact],” says Duma, who created the five-star rating system for commercially available helmets.
Still, there are several challenges to address before the helmets reach the playing field, Duma cautions. The magnets won’t do any good if a player’s head collides with a knee, a shoulder, or the ground. And to help in head-to-head collisions, the technology has to be universally adopted. “It has to be implemented by everybody. You can’t have just one team have it,” Colello says. “I mean, you certainly can, but it won’t have any effect at all.”