Is it mandatory for NFL players to wear pads? - Quora
NFL says players must wear thigh, knee pads in 2013 - ESPN : r/nfl
Health after the NFL: The highs and lows of a lineman's weight journey
Three Simple Fixes That Could Save Pro Football
NFL rules video reminds players of new horse collar rule - NBC Sports
N.F.L. Gives Lower-Body Padding a Tryout - The New York Times
You've Got Mail: Panthers Week
Brian Robinson and the 15 'super seniors' who can benefit most from extra year: NFL Draft Watch for Week 2 - The Athletic
NFL players must adjust to new padding requirements -- or else
NFL history: 100 people who shaped the league, pro football - Sports Illustrated
NFL Health and Safety Related Rules Changes Since 2002
NFL Health and Safety Related Rules Changes Since 2002