The NFL requires Guardian Caps for most players during practice, but the technology remains optional during games.

But in recent years, the NFL believes it has found a way to at ... That includes not just Guardian Caps but also inventions like Q-Collars, which are touted to reduce the effect of repeated ...

In the NFL, which is beset by the specter of concussions, the Q-Collar has “ambassadors” on the Kansas City Chiefs, Los Angeles Rams, and Chicago Bears, among other teams, according to its ...

The devices began showing up on NFL sidelines a few years ago and are ... Coach Greg Spahn said the program received a grant to purchase 22 Q-collars to be used in games and practice by players.