NFL team owners voted Wednesday to enact a new safety measure that makes it illegal for a ball carrier to lower his head to strike a defender in some instances.

The rule, recommended by the league’s competition committee, takes effect in the 2013 season. It quickly generated criticism and controversy after the committee announced the proposal last week. But committee members and others in the sport called it a necessary and sensible player safety initiative.

“I just don’t think it’s that big of a change for us coaches,” Baltimore Ravens Coach John Harbaugh said earlier this week. “We just don’t coach [hitting with] the crown of the helmet. No coach at any level coaches the crown of the helmet. It’s just not part of football.”

Under the rule, it will be illegal for either a runner or a tackler to initiate contact with the crown of his helmet while outside the tackle box (the area between the two offensive tackles when they line up) and more than three yards beyond the line of scrimmage. Such an action will result in a 15-yard penalty.

Chicago Bears tailback Matt Forte took to Twitter over the weekend to criticize the proposed rule, suggesting that it would rob a running back of his ability to protect himself.

St. Louis Rams Coach Jeff Fisher answered this week by saying the rule was designed to encourage players to use their shoulders instead of their heads and eliminate head first techniques that can lead to serious injuries.

League officials said the rule is designed to eliminate only the most serious, obvious violations. When the league studied one weekend of games last season, NFL officials said, five violations of the new rule that would have resulted in penalties were seen.

Some coaches expressed concerns this week that it might be too difficult for officials to enforce the rule properly during games. But that didn’t prevent it from being ratified. Competition committee members said throughout the process they were confident that the rule can be called correctly by officials.

The NFL’s latest attempt to improve player safety follows other rule changes in recent years to protect players in defenseless positions, such as a quarterback throwing a pass or a wide receiver making a catch, from blows to the head.

The NFL faces litigation by thousands of former players over the effects of concussions.

The ban passed by a 31-1 vote, with only the Bengals voting against the proposal, according to a person familiar with the vote.

“Any time you have a rule change, how it’s officiated is a topic,” Dallas Cowboys owner Jerry Jones said. “… It’ll certainly make our runners more aware of what to expect. The main thing is, it’s pro-health and safety.”