"Loose-fitting football helmets tied to worse concussions in teens "- UPI.com

"Young athletes with loose helmets had the highest rates
of concussion symptoms, such as drowsiness, hyper-
excitability and sensitivity to noise. Their concussions
also lasted longer and were more severe, the study
found...."

http://www.upi.com/Health_News/2016/03/04/Loose-fitting-football-helmets-tied-to-worse-concussions-in-teens/7681457103375/