For reasons that remain unclear to experts, getting one concussion makes a person more prone to getting further concussions in the future. According to a study by Cantu and published in Neurosurgery, American football players who sustained three or more concussions were significantly more likely to develop depression had five times a greater chance of developing Alzheimer's disease.
"You can have the best helmet in the world, but if you're going head to head, you're still going to be at risk to get a concussion," said Dr. James Eckner, clinical lecturer in the department of physical medicine and rehabilitation at University of Michigan. "I don't want to discount efforts to make the game safer, but there are other things that also need to be done that would affect how people play."
Going along with that idea, in 2009, the NFL instituted a new policy where players could not return to a game or practice on the same day they exhibit concussion symptoms, including confusion, gap in memory, abnormal neurological exam, persistent headache or loss of consciousness.
And in 2010, the NFL took its policies one step further by charging hefty fines to players for particularly violent or flagrant hits, particularly blows to the head. Many doctors say they want to change the level of aggression that is such a part of football.
University of Michigan's Eckner said that a player can get a concussion -- even when he is not hit in the head. If the body is hit in a way that causes the player's head to accelerate and decelerate, no helmet can stop that concussion from happening.
"What really needs to happen is that the culture of athletes needs to change," said Eckner. "If you have kids being taught to lead with their heads, they're going to keep doing it."
Cantu said that creating a helmet that will better protect against concussions should be the highest priority in football safety.
"This legislation flames that priority," said Cantu. "I think it will facilitate even further discussion and funding. But how helmets relate to concussions is such a complex issue that we just don't have all the science today. Is that acceptable? No. Will it be that way in a year? I hope not."