Newer helmets reduced risk by 54% compared to older helmets design. A helmet designed in 2000 had less concussions than one designed in 1980. This shows that are technology is getting better and we are reducing even more concussions, but no helmet has been designed yet that prevents all concussions. Researchers started a experiment with 1800 football players on 8 college teams, a long with the number of concussions over a six year period (2005-2010) researchers identified that the new Riddell modell reduced concussions by 53.9%. The revoloution caused 8.37 concussions per 100000 head impacts versus the new Riddell helmet with 3.86 per 100000 head impacts. That is half as many concussions. Riddell is the most used football helmet in the NFL. In 2013 their was 121 concussions in one season which is averaging 7 concussions per week. Head injuries is definately the biggest issue concerning football.
Sometimes players intending for a harder hit on players they may use their helmets as a striking force to hurt other players. This could injure both players involved. To stop this reoccuring strategie penalties have been enforced to prevent it. Researchers have found that if you at a foam layer to the helmet it reduces the potential for injury.
Sources: momstream.com, sciencenews.com, foxnews.com, medicaldesign.com, hawaii.edu, ncbi.nln.nhi.gov