How Do Football Helmets Work?

At the halfway mark of another heart-pounding NFL season, player injuries have included everything from minor scrapes, scratches and bruises to major sprains, strains and pulls.

Fortunately, however, severe head injuries are rare in the NFL, even though players take a beating every Sunday afternoon for 16 weeks—including blows to the noggin powerful enough to rattle fillings.

Protective helmets save players from major head trauma—but who knew helmets vary widely by sport?

“Football helmets use a suspension system designed for repeated hits, whereas helmets for skiing, biking and motor sports use a ‘sacrificial’ design intended for one-time hits,” says Jasper Shealy, world-renowned expert on sports helmet use and professor emeritus of industrial and systems engineering at Rochester Institute of Technology.

“The different designs represent trade-offs,” Shealy explains. “Suspension-system helmets prevent football (and hockey) helmets from having to be replaced frequently during a game because of repeated hits. But they’re not as good as a sacrificial design for a severe hit where the inner liner crushes and fragments.” Shealy emphasizes that “sacrificial” refers to the helmet, not the wearer.

Now, the next time you’re sitting around TV watching the big game, impress your buddies with your newfound knowledge of helmets. And, appreciate the big hits even more, knowing that helmets and other protective gear make them bearable.