This football season, the debate about head injuries has reached a critical mass. Startling research has been unveiled. Maudlin headlines have been written. Congress called a hearing on the subject last month.

As obvious as the problem may seem (wait, you mean football is dangerous?), continuing revelations about the troubling mental declines of some retired players—and the ongoing parade of concussions during games—have created a sense of inevitability. Pretty soon, something will have to be done.

But before the debate goes any further, there's a fundamental question that needs to be investigated. Why do football players wear helmets in the first place? And more important, could the helmets be part of the problem?

"Some people have advocated for years to take the helmet off, take the face mask off. That'll change the game dramatically," says Fred Mueller, a University of North Carolina professor who studies head injuries. "Maybe that's better than brain damage."

The first hard-shell helmets, which became popular in the 1940s, weren't designed to prevent concussions but to prevent players in that rough-and-tumble era from suffering catastrophic injuries like fractured skulls.