The NFL put 10 helmets on a prohibited list from a total of 34 that were tested by biomechanical engineering consultants, who conducted their research at a lab in Ottawa, Canada.
The prohibited helmet models are: Rawlings' Impulse and Impulse+, Quantum and Tachyon; SG Varsity and SG 2.0; Schutt Vengeance Z10 (model 204100), Air XP (model 789002) and Air XP Pro (model 789102); and Riddell VSR-4 (model R41133).
Riddell and Schutt both manufacture models that tested among the best helmets in the rankings.
In prior seasons, NFL players could choose any helmet as long as it passed National Operating Committee on Standards for Athletic Equipment (NOCSAE) certification standards.
The NFL notes that this study is one component of a player's assessment when picking a helmet; other factors like fit, player position, and past medical history also contribute to the decision.
Players who wore the prohibited helmets during the 2017 season will be allowed to continue to wear them in 2018 but not beyond that season.
"And 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. We are encouraged this is an important step for better player safety". And the goal of continuing to rank the helmets, and the objective of the joint decision to prohibit certain helmets this year, is to increase that continued movement into better-performing helmets'.
The 2018 version of Vicis' ZERO1 helmet ranked No. 1.
"The objective of the continuation to rank helmets and the joint decision with the players' association to prohibit is to increase that movement into better performing helmets".
Made by a five-year-old Seattle-based startup, this helmet boasts a pliable outer layer rather than the hard plastic that's traditionally favored by players, according to Inc.com.
Two companies, Ridell and Schutt, claim 90 percent of the US market.
The NFL reached a $1 billion concussion settlement in 2017; the league is now dealing with alleged "fraudulent schemes by doctors, lawyers and players to illicitly tap the uncapped fund", The Wall Street Journal reported last week.