AS EVIDENCE KEEPS mounting that playing football for years can cause brain injuries, leagues at all levels have a responsibility to athletes. Pop Warner, the football organization for kids ages 6 to 13, is taking reasonable first steps to reduce the risks. Starting in August, the organization is limiting contact to 40 minutes per practice and banning head-on drills where players line up more than 3 yards away from each other. It’s a better path than the hands-off approach espoused by the other major football group for kids, American Youth Football.

There’s ample reason to set limits. The Pop Warner organization, which has about 300,000 players nationwide, pointed to a study showing that 5 percent of head hits to players approached impact levels that risk concussions in adults. Julian Bailes, Pop Warner’s top medical adviser and a former physician for the Pittsburgh Steelers, also highlighted reports that 60 percent of head-on-head contact happens at practice. Those statistics look especially troubling in light of research by Boston University suggesting that repeated low-impact head contacts may cause significant injuries for teenage players over the long term.

Pop Warner’s rule changes are the latest in a promising trend; the NFL last year sharply reduced the number of full-contact practices and made several in-game changes to curtail high-impact collisions. Pop Warner would be wise to consider further limits, including those that affect games, not just practices. Wisely, the organization hasn’t ruled out a ban on the three-point stance, which puts linemen in the position of starting plays with heads out front.

American Youth Football, which has teams in every state, has shunned hard-and-fast constraints on practice so far. Its president, Joe Galat, argued that Pop Warner has gone “overboard” and that the health risks are better addressed through proper coaching, sportsmanship, and refereeing. But with damage to football-playing adults becoming increasingly evident, parents should ask Galat why it’s “overboard” to take greater precautions for children.