–
crack! The sound of ball caps crashing on the field is an audible signal that fall is just around the corner.
But that voice comes with a dark side. Scientific evidence shows that repeated blows to the head — even if they don't cause a concussion — can cause permanent damage to the brain and possibly the development of neurodegeneration called chronic traumatic encephalopathy, or CTE.
The problem has set off alarms at all levels of the sport, with coaches, trainers, parents and leagues grappling with tough questions about whether football is safe for athletes.
Just last month Three young players They died playing football, two with head injuries. The third death is still under investigation.
Ryan Craddock, father of 13-year-old Cohen Craddock, after his son's death It is called. All student players to wear protective caps with extra soft padding. They are not helmets but flexible padded covers that slip over the player's existing helmet.
“If my son had been wearing something like that, I believe it would have had a completely different outcome,” Craddock told . “You're not fixing the hat. It's a direct link. So why not just get that extra layer of protection?”
Intuitively, putting extra padding on a football player's head may seem like a good idea, but there are few independent studies that show that it reduces the force of blows to the head or prevents head injuries.
Laboratory studies in which researchers simulate head impacts show that the helmets reduce impact forces. But the few published studies that tested exercises on college football players found no benefit compared to helmets. There are no published independent studies that have attempted to measure whether Guardian Cups can reduce concussions or head injuries in players and work for young players.
Caps got a big boost from the NFL, which now allows guards All players to wear during the regular season Games. The league mandates contact for most players at every preseason practice, as well as regular and postseason practices.
The cap maker, Guardian Sports, says its own extensive testing, as well as years of use by many major college football teams, shows it reduces injuries on the field.
“We tell anyone who asks that no product guarantees a player's concussion,” says Erin Hansen, who started Guardian Sports with her husband in 2011.
“But our product has passed the proof-of-concept point well. We now have over 12 years of on-field data and feedback from over 500,000 players who have used Guardian Cups. Schools like UGA, Ga Tech, Alabama, Tennessee don't use a product year after year that doesn't work for their players. The NFL and CFL certainly won't oblige the Caps if the data isn't clear,” Hanson wrote.
Dr. David Camarillo, an associate professor of bioengineering at Stanford University and a former college soccer player who tested Guardian Cups, said he doesn't think the evidence is very clear.
“I think the reason is, football is in big trouble. People worry about CTE. We're seeing kids die,” Camarillo said. “People want to try something as long as they don't think it's going to hurt.”
On its website, Guardian mentions the XT model It reduces the effect Up to 33% per player's head, while the beefier model used by the NFL reduces head velocity in collisions by 40%.
NFL Vice President Jeff Miller told Coy Wire that the helmets made the players safer.
“Over the last two seasons, we've had a 50% reduction in concussions in the positions we've allowed us to wear them. So of course we said, 'OK, all positions will now wear them in the preseason.'” Miller said.
The data behind the NFL's claim is not public, however, leading to doubt among some scientists.
“It's hard to take what the NFL is saying at face value,” Camarillo said. “What they really need to do is share the data publicly, not just publish it, but release it” and fund independent studies that confirm their conclusions.
The league said it plans to publish studies soon to support the results.
“Obviously, there are papers in progress that have been submitted to journals right now. They're under review, so you should see that in print. You know, it takes a while to get things published, but it's in progress,” said Dr. Allen Sills, the NFL's chief medical officer.
One reason the studies published by Sills may appear to conflict with the NFL's results is that the Guardian Cap has changed over time.
“Some of the older cap models did not show any benefit in our tests, but the new version of the cap showed this reduction in the lab,” he said.
In 2022 Position statementThe National Athletic Trainers Association cautions against the use of aftermarket helmet add-ons such as Guardian Caps, stating that “current evidence suggests no benefit.”
Several groups of independent researchers recently tested Guardian Caps in the lab and in the real world, and they say the jury is very much out on whether they work or not.
Studies in two labs measuring the force of twisting and side-to-side impact on the head show a measurable — if small — benefit.
Researchers at Virginia Tech's Helmet Lab put several helmet models through repeated crash tests to mimic the way players hit their heads on the field.
Lab director Dr. Steve Rowson, a biomedical engineer, said the test showed that Guardian Caps reduce impact force, especially if the thick model deployed by the NFL is used and both players have them on.
Rowson said his tests showed that the standard model of the Guardian Cup reduced acceleration by 5%, while the model used by the NFL reduced linear velocity by 14%.
The reduction was even greater when the experiment simulated the effects of two players each wearing a Guardian's cap.
“We've seen results double,” Rawson said. He said the lab test could reduce the risk of seizures by 15 to 35 percent.
The Virginia Tech study, however, was not published in a peer-reviewed journal. The group said it had a paper under review, and published it Summary of findings Online.
Many more published studies by independent researchers sought to reduce the impact on players on the field but failed to find it.
Two studies conducted by researchers at the University of North Carolina and the University of Nevada, Reno, used special sensors to measure head impacts on college football players and found no difference between players who wore helmets and those who did not.
University of North Carolina Research They followed 10 Division I college football players through 14 practices in the fall of 2022. Half of the guard caps are worn over the normal helmet; The other five did not.
All helmets are equipped with special sensors to measure head impacts. Cameras were used to ensure that measurements were related to actual hits and not just false positives.
The researchers measured and observed nearly 1,000 balls and found that there was no difference in power between players who wore protective caps and those who did not. The study was published in the October 2023 issue of the International Journal of Research and Public Health.
Similarly, the Research Researchers at the University of Nevada, Reno found no benefit from using protective caps in football players.
The study followed seven players in six practices. For half of the practices, they wore the extra layer on their hats; For the other three they did not. All players wear special mouth guards to detect head impacts.
The researchers recorded more than 800 video-verified hits.
“There was no difference after the protective caps were applied,” said Dr. Nicholas Murray, an associate professor at the University of Nevada who worked with graduate student Christine Quigley. Their study was published in June in the Journal of Athletic Training.
Given all the known science on Guardian caps, “I don't think we can honestly answer the question, if these are protective or not,” Murray said.
A third recent study by Stanford researchers split the difference. When Camarillo and his team tested the Guardian Caps in the lab, they found that the extra padding reduced the force of the impact. But when they put it on the players on the field, there was no significant difference between those who wore a protective cap and those who didn't.
Rawson, of Virginia Tech, thinks the studies that tested players on the field may have been small and lacked enough data to rate the benefits of the replicas.
Murray at the University of Nevada, Reno says there is no doubt that laboratory testing is necessary. Conditions in the laboratory are carefully controlled and the tests can be repeated.
But real-life studies are also important, he said. The results of laboratory studies do not always translate directly to real life.
“It's where real people get involved on the field and where real behavior applies,” Murray said.
Murray said forces measured in the lab don't directly translate to concussions or head injuries on the field, and those are what head injuries are trying to prevent.
In the lab, scientists measure acceleration in terms of the G-force, or force of gravity. There is no limit to the G forces that determine whether a hit will definitely cause brain damage.
Increasingly, science indicates that repeated blows to the head injure the head, perhaps even more than the force of the blow itself.
“I've seen concussions that aren't concussions, where the linebacker comes off the bench, hits his head and comes to the sideline and says, 'Oh my goodness, I feel terrible.' And now I see the wide receiver they got…