If we want to cut down on football concussions, should we bring back the leather helmet? Not quite, says a new study in the Journal of Neurosurgery, though the noggin-protectors of yore do at least as good of a job as modern helmets at staving off concussions.
Modern helmets do a much better job of preventing deadly skull fractures. But on the type of lower-impact hits to the head you typically see in college and high school games — the constant subconcussive blows that can also cause brain damage — leatherheads do a comparable, and sometimes better, job of reducing concussion risks than today’s helmets, according to Cleveland Clinic researchers.
“The fact that leather helmets were even in the neighborhood with modern helmets was surprising,” says Adam Bartsch, the study’s lead researcher and director of the Spine Research Laboratory at the Cleveland Clinic’s Center for Spine Health.
To reach this conclusion, Bartsch says his team basically “smashed some helmets together.” In the experiments, 11 widely-used high school football helmets and two vintage turn-of-the-century models were placed on the heads of crash-test dummies. The researchers simulated head impacts at gravity-force (Gs) levels of 75 Gs or less, which are typically encountered in high school and college games. They simulated impacts at different angles – a head-on collision, a hit to the side of the head, a hit to the back of the head – and measured their effects on skull rotation, neck force, neck torque and other head movements.
This data was input into a software program that estimates risk of brain contusions, acute subdural hematoma (bleeding on the surface of the brain), and diffuse axonal injury (DAI), which causes the shearing of nerve cells within the brain. “Overall,” the study concludes, leather helmets and modern helmets provide a “similar protectiveness profile” during subconcussive hits. In fact, under one testing scenario, a leather helmet provided a lower level of DAI risk than any of the modern helmets.
How could a leatherhead possibly be more protective? One reason, Bartsch says, probably has to with the stiffness of today’s helmets. While these helmets are effective shields against catastrophic skull fractures, they don’t do as good a job absorbing energy from a lower impact hit. These hits might not break the skull, but they can cause the brain to shift a little bit within the skull. And such jiggling causes concussions.
Bartsch offers a useful analogy: Think about hitting your thumb with a hammer. If you put, say, a piece of a padded gym mat on your thumb, that padding will absorb the impact from the hammer, and dull the pain. Now, imagine putting a two-by-four on top of your thumb. Whack the hammer against that stiffer surface; your thumb will probably hurt more than the gym mat. Think of the leatherhead as the gym mat, and a plastic helmet as the two-by-four. The hammer is like a football hit, while the thumb is like your head.
Still, we won’t be returning to the leather helmet days; no one wants fatalities on the football field. Yet it’s worth considering whether today’s football helmets might benefit from a slightly softer outer shell.
For inspiration, Bartsch suggests that the sporting-goods industry look at car companies. “Unlike cars, in which seat belts, airbags and crumple zones make the choice between a 1920s Model T and the modern mini-van a no-brainer,” said Bartsch in a release that accompanied the study, “these results tell us that modern helmets have ample room to improve safety against many typical in-game hits.”