Over the course of three seasons, only two hits to the heads of University of Rochester football players resulted in concussions. Sounds like pretty good news? Not so much. The other 19,126 hits among 38 players—as measured by helmet sensors—may have been smaller and did not result in immediate concussion-like symptoms, but researchers say they still took a serious toll, reports the Rochester Democrat and Chronicle. Specifically, "two-thirds of the players experienced a decrease in the structural integrity of their brain," per a university news release. Researcher Adnan Hirad describes a "kind of fraying" in the white matter of the players' midbrain, which controls vision and hearing functions, per the New York Times. Ringing ears and inability to focus would be eventual repercussions.
"Public perception is that the big hits are the only ones that matter," says Brad Mahon, senior author of the study in Science Advances. Those are obviously bad, "but the public is likely missing what’s causing the long-term damage in players' brains," he adds. "It's not just the concussions. It's everyday hits, too. And the place to look for the effect of such hits, our study suggests, is the midbrain." In fact, Hirad calls the midbrain region the "canary in the coal mine" for brain injuries. One interesting nugget from the research: Most of the hits to the head, 59%, came during practice, notes Smithsonian. By contrast, 37% took place during official games, with the remainder during scrimmages and the like. (Bob Costas says he was yanked from NFL coverage for speaking out about the NFL's concussion problem.)