The rationale is simple: Players, feeling more vulnerable, will learn safer tackling technique, which they will then bring to the field on full-padded game days. “The idea of taking off the football helmet during practice to reduce head impact may seem counterintuitive to the sport,” said Erik Swartz, a professor of kinesiology at the University of New Hampshire. “But the findings show that preventing head impacts, which can contribute to spine and head injuries like concussions, may be found in behavior modification like these drills.” Swartz tested the efficacy of helmetless practice with his university’s football team in a study published in December in the Journal of Athletic Training. Although limited in scope, the results strongly suggest that players who went helmetless for even a portion of practice experienced significantly fewer head impacts “per athlete-exposure” over the course of the season. Fewer head impacts, it is reasonable to think, lead to fewer concussions.

To be sure, broader research is needed to confirm the implications of Swartz’s findings at all levels of play. In fact, the Centers for Disease Control and Prevention will lay the groundwork for such a study, having just announced plans to evaluate the risks of helmeted tackling in youth football. Almost assuredly, though, players will be safer during games if they learn to block and tackle without their helmets during practice. A first step toward that goal would be to develop practice helmets with easily removable facemasks, which would leave players feeling less invincible and more open to learning safe-tackling techniques. But however we get there, returning the helmet to its rightful role as protection against unintentional collision rather than armor for premeditated mayhem is the best of a diminishing set of solutions posited to decrease incidences of concussions and other head trauma.