Concussions in Football

This season, the NFL has changed several rules to try to reduce player injuries, especially concussions. Research done by a team at Purdue on football injuries has shown that in a typical hit, a player can experience around 40 g's, and in "big hits," players may experience almost 300 g's, measured by sensors in helmets.

One of the new rules is that kickoffs are now 5 yards closer, meaning defending players will now have 5 yards less distance to run before engaging in tackles. The idea behind this is that players running down the field after a kickoff will have less velocity before making tackles, which would reduce the acceleration players experience during hits.

Concussions are a result of the brain experiencing a rapid deceleration after colliding with the inside of the skull. The brain is surrounded by fluid, so it can move around inside the skull relatively independently of the head itself.

http://www.npr.org/2011/08/14/139621182/at-last-football-faces-concussion-problems-head-on

http://www.slate.com/id/2281515/

http://www.webmd.com/brain/tc/traumatic-brain-injury-concussion-overview