The clampdown comes after a record number of concussions in a single season.
Monday 16 April 2018 20:27, UK
The NFL and the NFL Players Association has banned specific types of helmets for the first time in a bid to improve player safety.
The decision was based on the latest annual laboratory tests used to assess helmets, from best-to-worst performing.
A total of 10 helmet models have been banned, six immediately with another four phased out by 2019.
It comes after a season in which players suffered 281 concussions - the highest on record.
Around 200 players wore helmets last season that now would be prohibited, according to Jeff Miller, the NFL's executive vice president of health and safety initiatives.
"We've begun to see that over the last couple of years, players [are] moving from helmets that rank in the poorly-performing areas to those that are ranging closer to the top-performing helmets," he said.
"We think that is an important move, and we think that will improve player health and safety.
"The purpose of continuing to rank the helmets, and the purpose of the joint decision to prohibit certain helmets this year, is to increase that continued movement into better-performing helmets."
The NFL has been ranking helmets based on laboratory testing, for four years.
The latest move comes after the NFL's chief medical officer, Doctor Allen Sills, called the current level of concussions "unacceptable".
In March, league owners agreed to a significant rule change regarding head contact on the field of play.
Playing Rule Article 8 states: It is a foul if a player lowers his head to initiate and make contact with his helmet against an opponent. The player may be disqualified.
