CFL introduces mandatory extra helmet protection for multiple positions. As well as other new health & safety measures. : r/sports
Once shunned by NFL, 'disruptive' helmet inventor believes his time has come
Football helmet with liquid padding may prevent concussions
NFL, NFLPA approve concussion-reducing helmet for quarterbacks
Football helmet - Wikipedia
New high-tech helmets may protect American football players from debilitating concussions
Riddell launches Axiom, latest helmet to combat concussions
Smart football helmet may help detect concussions
Football helmet - Wikipedia