A new helmet design called SpeedFlex introduces new technology
This Flexible Football Helmet Absorbs Hits Like a Car Bumper
SPEEDFLEX, Varsity, Helmets, Open Catalogue
A-Flex Plus Adjustable Protective Headgear by Orthomerica
Revolutionary new ZERO1 football helmet may help NFL players
Study: Better Football Helmets Needed to Prevent Concussions
The Zero1 Flexible Football Helmet May Save Players' Brains
Teen's woodpecker-inspired system aims to reduce football concussions
Electronics, plastics and football at Gallaudet University; faster
Football helmet - Wikipedia