What does playing tackle football do to young brains?

The controversy continues
mike dupris, flickr.com, CC BY 2.0
Mike Dupris, flickr.com, CC BY 2.0

With the brutality of professional American football under fire, recent studies show kids under 12 playing tackle football face increased threats to their developing brains.

Participation in youth tackle football before age 12 raised the risks of developing problems with behavioral regulation, apathy, and executive functioning by twofold and of clinical depression by threefold, as stated in a study published in Nature’s Translational Psychiatry in September 2017.

This study was led by the Boston University and found that age and symptom severity in children were linked, i.e. the younger children are when they first play tackle football, the worse these symptoms may manifest.

The study focused exclusively on tackle football, which involves full-contact tackling and blocking and other rules similar to those of the National Football League (NFL). Flag football, which eliminates tackling, is a less physical version of the game; it was not examined in the study.

These findings in children follow Boston University’s well-publicized paper in JAMA showing evidence of chronic traumatic encephalopathy (CTE) in 110 of the 111 brains of deceased adult NFL players who had donated their brains for study. CTE is a progressive degenerative disease of the brain found in people with a history of repetitive brain trauma.

The human brain is finished growing to its full volume around 8 years of age – but important connections of the functional networks still continue to develop until around 22, said Nico Dosenbach, a pediatric neurologist who specializes in treating brain injuries at Washington University School of Medicine, St. Louis.

Having a full-grown – but still developing – brain makes children especially vulnerable to the types of globalized hits common in tackle football in two ways, he said.

“As an adult, your body is bigger and your neck muscles are stronger. So, if you get run into, your body will absorb more of the hit than a child’s would.”

First, a young child’s head is still disproportionate to the body.

“As an adult, your body is bigger and your neck muscles are stronger. So, if you get run into, your body will absorb more of the hit than a child’s would,” said Dosenbach, a fellow of the Jacobs Foundation, parent organization of BOLD blog. “A child’s brain would thus take on more of the impact.”

Second, recovery from a global traumatic brain injury – such as a high-impact hit to the head from a tackle – is far more difficult for children because their fundamental connections are not well established, he added.

“The realization in the past 10 years is that you can’t change one part of the brain without changing the whole thing. It is a unilateral, interconnected network,” he said. “That means the worst kind of injury is the kind that hurts everything in a brain.”

With respect to contact intensity, a 2016 study by Virginia Tech found that six percent of recorded head impacts occurring in kids younger than 14 playing tackle football exceeded a force 40 times greater than gravity.

“The trend is that as kids get older, they play football faster and more often. As a result, they get hit harder and more frequently,” says Steven Rowson, assistant professor of biomedical engineering at Virginia Tech and co-author of the study. Most of those high-impact hits came during drills used in practices, earlier research showed.

“As kids get older, they play football faster and more often. As a result, they get hit harder and more frequently.”

As this research comes to light, the number of kids playing football has fallen. The Aspen Institute’s 2017 report The State of Play found the percentage of kids aged six to 12 who participated in tackle football fell from 3.8% in in 2010 to 3.3% in 2016.

As these concerns about head injuries became widely known, Pop Warner Youth Football League, the oldest and largest U.S. youth football league, has been adjusting its rules, forbidding full speed head-on blocking or tackling drills in practice and limiting contact time at practice.

Not every medical professional holds deep concerns about youth players. Julian Bailes, director of neurosurgery and co-director of NorthShore University HealthSystem Neurological Institute, Evanston, Illinois, said that he is “not particularly worried” about kids playing tackle football. Bailes is chairman of Pop Warner’s medical advisory committee, a volunteer position.

“There is no scientific consensus that kids 12 or 14 shouldn’t engage in contact sports.”

“There is no scientific consensus that kids 12 or 14 shouldn’t engage in contact sports. There are millions upon millions of men who played youth contact sports and are fine,” he said.

While debate about football’s impact will certainly continue, no one questions the importance of sports in keeping children active and healthy. “There are a lot of remaining questions about football’s impact that we don’t have great answers to right now,” Virginia Tech’s Rowson said. “But there are a lot of opportunities to make all sports safer for kids.”

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