Football helmets protect skulls. They don’t protect brains.
© 2015 Roy Benaroch, MD
A few weeks ago, I wrote about concussions—mild brain injuries caused by trauma. There’s increasing concern that repeated concussions—that is, repeated brain injuries—aren’t good. They can lead to depression, intellectual decline, movement disorders, and other kinds of symptoms that you’d expect from someone whose brain has been injured multiple times.
One tack that athletics departments are taking is to invest in more-expensive helmets. The idea has some appeal—wrap your head in something protective, and then you can bash it into things safely. But there’s a fundamental misunderstanding here. Helmets, the best helmets, can do a really good job at protecting your child’s skull from damage. But no helmet in the world has ever been shown to provide any protection for your child’s brain.
Think about it. The helmet protects the outside of your head, the hair, the skin, the eyes the cheekbones, all of those. People wearing helmets do not get lacerations of the scalp, and they don’t fracture their skulls, because the helmet protects these body parts from damage. But the brain, that is a very different story.
Your brain floats on the inside of your skull, enveloped in fluid. It gets injured not by directly smashing into someone else’s head, or into the ground, or into a windshield. The brain doesn’t strike your steering wheel and it doesn’t get hit by a hockey puck or a boxer’s gloved fist. What strikes your brain, and what causes the damage, is the inside of your own skull.
Picture this: you’re in a speeding car. You, your head, your skull, and your brain are all traveling 60 miles an hour when you swerve off the road into a concrete pole. Very quickly, you and your head stop moving—BAM, you’ve decelerated from 60 mph to zero in just a fraction of a second. If you’re lucky, your head is protected by snapping forward not into the windshield or your steering wheel, but into a relatively-soft air bag. Air bags do a great job to protect skulls and heads. But what happens to your brain? As smart as it might be, brains follow the laws of physics, too. It was just moving at 60 mph, and the thing carrying it, the skull, just stopped. The brain then slams into the front of the skull, from the inside, at 60 mph.
There is no airbag in there to protect the brain. In a car accident, the brain just slams into the inside of the skull. And in a football injury, the same thing happens—the helmet protects the scalp and the head, sure, but the brain still slams into the skull from the inside. Unless they figure out a way to implant a little helmet inside the head, between the brain and the skull, there’s nothing in there protecting the brain.
It’s worse, by the way. The really bad concussions—the most serious brain injuries—come from the brain slamming sideways into the side of the skull, or from rotational forces that shear the cortex, the top thinking part of the brain, away from the base (think of slapping a top from the side and watching it spin. Whee! Brain!) In any scenario, the physics are the same—forces act on the skull to change its motion, and the brain slams into the skull from the inside.
Good sports equipment is still essential for athletes, and I don’t mean to minimize what a good helmet can do. I don’t want poked out eyeballs or broken jaws or caved in skulls, either. But I’d also like to see a more-honest discussion of brain injury in sports, and what we can and cannot do to prevent and mitigate the effects of these injuries. We’re not getting honest info from the helmet manufacturers, that’s for sure.