A recent study found that at least 25% of former NFL players who died between 2016 and 2021 had chronic traumatic encephalopathy (CTE), a degenerative brain disease.
David Camarillo, a former football player at Princeton University, researches the biomechanics of concussions in his lab at Stanford University.
Camarillo's team developed a mouthguard with sensors to measure the forces on impact.
"Concussions can happen in many ways. It can be a hit to the head. It can be a hit to the body where you have a whiplash injury," said David Camarillo, Ph.D., an associate professor of bioengineering at Stanford University.
Camarillo says that a blow to the head makes soft brain tissue slide and shake inside the skull. He especially points to slight twisting motions as a cause of brain injuries.
Helmet safety is much improved when Joe Montana was leading the 49ers to Super Bowl wins. Back then, helmets were just designed to prevent skull fractures.
"If you go back to those days, it was basically hard plastic and some version of a relatively generic foam that was on the inside of the helmet and that was about the extend of the design," explained Jeremy Erspamer, CEO of Certor Sports.
At the time, little attention was paid to brain injuries.
That started to change when former linebacker Junior Seau died by suicide. His family donated his brain for research, and it showed brain damage.
That ignited the conversation about the effects of repetitive head trauma.
"What happened to Junior Seau has evolved the way in which we design our products. It's evolved the way we test our products to make sure we are paying equal amount of attention to the high impact concussive type events but really paying equally amount of attention to lower impact repetitive testing," said Esparmer.
Certor Sports supplies helmets to about 40% of NFL players under the brands Schutt and VICIS.
The newest designs now have micro lattice cushioning that's 3D printed with different impact absorption points depending on the position of the player.
"We can put added impact absorption in the back of a quarterback's helmet because they're mostly taking the helmet to ground impact. Whereas an offensive or defensive lineman, we put more protective absorption material up in front of the helmet," said Ersparmer.
The NFL also requires additional head protection during practices when there will be contact.
Guardian Caps go over the hard helmet shell and provide additional padding. Wearing them during games is optional.
Camarillo was testing Guardian Caps when his team detected that the facemask area is another crucial impact point for brain trauma.
"In football in particular, a lot of the concussions and impacts are actually to the faceguard area," said Camarillo. "When you get hit low enough on the faceguard, the forces don't go through the helmet; they go through the strap."
Camarillo's team developed a wearable shock absorber for the chinstrap.
"During an impact, the liquid is squeezed from one chamber out into another chamber and then it returns and it's using that motion of the liquid in order to dampen the forces and protect the brain," explained Camarillo.
Marketed under the name SoftShox, the chinstrap reportedly reduces the intensity of head impacts by 35%.
Despite all the attention being paid to NFL head injuries, Camarillo said that cyclists make up the majority of head injuries.
If you are interested in checking the safety rating of consumer helmets, Virginia Tech developed a helmet safety rating system for all types of sports and construction work.