Helmets don't eliminate concussions. It's time for the NFL to
NFL report: concussions dropped 50 PERCENT when players wore new
Guardian cap' to prevent head injuries mandated for practices, CFL
If a player wanted to wear a Guardian Cap during a game, the
Padded helmet cover shows little protection for football players
Guardian Cap used by football teams to protect against head injury
Football Guardian Cap draws mixed reviews from players, experts
NFL hopes to reduce head injuries with 'goofy' helmet experiment