From Purdy to Rodgers: the most important people in the new NFL season, NFL
Guardian Caps: NFL requires use of helmet cover at training camps to reduce head injuries
Why Alabama football players are wearing padded helmets in practice
Bombers welcome introduction of new safety gear – Winnipeg Free Press
So what exactly is that black padding on the Syracuse football helmets seen during practice?
$2 Million in NFL Funding Now Available to Help Innovators Create a New, Top-Performing Football Helmet for Submission to the NFL Helmet Challenge
NFL players wear Guardian Caps to reduce head trauma during training camp
Guardian Caps', NFL's Most Recent Attempt At Preventing Head Injuries
EXPLAINER: NFL using helmet caps for player safety, research