A study published in August 2026 found that at least one in four NFL players who died between 2016 and 2021 had chronic traumatic encephalopathy, or CTE. The British Medical Journal reported that of 878 players who appeared in at least one NFL game and died during that six-year span, at least 25% had CTE, a figure the study’s lead author called a low-end estimate. The league said it “continuously strives to make the game of football safer, including by implementing strategies to reduce concussions and head impacts.”
One of those strategies is the use of Guardian Caps, large soft-shelled pads worn over helmets intended to reduce the risk of concussions and other head injuries during play. NFL testing indicates the cap can absorb at least 10% of the force of a hit, according to NFL research. The league does not market the caps as concussion-preventing devices.
Guardian Caps trace to Guardian Sports, founded in 2011 by Erin and Lee Hanson after an initial approach in 2010 to develop a flexible helmet shell. The product has been used in football practices since 2015 and underwent several design changes: early fixed straps gave way to elastic straps, and in 2017 a rubber flap and Velcro reinforcement were added. That year the cap won the inaugural NFL HeadHealthTECH Challenge, a competition funded by the league.
The current model, called Guardian NXT, was made for the NFL and features additional padding that “floats” at the top of the helmet. That floating design is intended to allow the cap to move with the helmet and reduce the risk of neck injury. The league subjected the caps to extensive testing before wider on-field experimentation.
The NFL began formal testing after simulated-impact studies covering 2015–19. A memo went to team medical and equipment staff in August 2020, and the Jacksonville Jaguars tested the caps that year. The league approved practice use for offensive and defensive linemen in 2021. Players are required to wear Guardian Caps during training camp practices but may be exempt if they select one of six new helmet models that provide equal or better protection, according to the league and the NFL Players Association. The NFL first authorized the caps for regular-season and postseason game use in 2024, and more players have chosen to wear them on game days since that approval.
