Altitude may affect concussions

Studies connect high elevations with lower concussion rates

By Tara Bannow / The Bulletin / @tarabannow

The day in the life of a woodpecker involves a whole lot of smashing its head against things at high speeds.

The reason the birds’ brains don’t turn to scrambled eggs is because they appear to have mechanisms that cause their noodles to swell inside their skulls just before impact, researchers theorize. Concussions, some researchers say, don’t happen because of the direct impact; rather, the impact causes the brain to “slosh” around inside the skull, causing the real damage. The brains of woodpeckers, by contrast, don’t have as much room to move around.

“It kind of creates a bubble wrap around the brain, filling the vascular tree in the brain, and kind of makes it a snugger fit,” said Greg Myer, director of sports medicine research at the Cincinnati Children’s Hospital Medical Center.

Myer’s research seeks to bring those same mechanisms in animals’ brains to humans in an effort to prevent concussions from happening in high-impact sports such as football, soccer and volleyball.

After reviewing concussion data from both the National Football League and high schools nationwide, Myer and his team theorize that simply playing at a higher altitude achieves that swollen brain effect. At high altitudes, the brain senses there is less oxygen and pulls in more blood volume to compensate, thereby causing it to fit tighter inside the skull and reducing sloshing.

The finding could have implications for athletes here in Bend, a city with an elevation of about 3,600 feet above sea level. Elevations in the NFL and high school athlete studies ranged from 7 feet up to 6,903 feet above sea level.

The researchers first studied data on concussions sustained by athletes at about 500 U.S. high schools between 2005 and 2006 and 2011 to 2012. The data spanned 20 high-impact sports, including football, baseball, wrestling, volleyball, soccer and basketball. The results, published in the November 2013 issue of the Orthopaedic Journal of Sports Medicine, concluded that sports played at high altitudes saw 31 percent fewer concussions versus low altitudes.

But critics argued that different parts of the country play sports at different skill levels. High school football players in, say, Texas or Florida might hit harder during plays, resulting in more concussions, Myer said.

So the team turned its sights to a different data set, one in which the level of play is nearly identical across fields: the NFL. They studied the concussion rates among the 16-game seasons in 2012 and 2013. The games were held in stadiums as low as New Orleans’ Mercedez-Benz Superdome at just above sea level to Denver’s Sports Authority Field at Mile High at about 5,200 feet above sea level.

The researchers found players’ risk of sustaining concussions was about 30 percent less at higher-elevation fields, or anything above 644 feet. The results were published in this month’s Journal of Orthopaedic & Sports Physical Therapy.

“We went down that pathway and again found interesting results,” Myer said.

To slosh or not to slosh?

Dr. Robert Harbaugh, director of Pennsylvania State University’s Institute of the Neurosciences, said he’s not sold on the sloshing theory that underlies Myer’s altitude research.

The neurosurgery and engineering science and mechanics professor said that theory assumes the brain is like a grape floating in a glass of water, but it’s not.

“The fluid outside the brain also penetrates the brain,” he said. “The brain is more like a sponge.”

Overall, Harbaugh said, the notion that altitude affects concussion risk is interesting and deserving of further exploration, but it’s far from proven.

Myer’s team is not slowing down. In fact, the researchers are in the early stages of studying a device they created that an athlete would wear around his or her neck during game play.

Myer can’t provide much detail yet but said the device mimics the hyoid apparatus in woodpeckers, an attachment site for throat and tongue muscles that Myer says throws out the bird’s tongue before impact, which restricts the jugular vein and causes the carotid artery to push more blood to the brain.

Trials of the device on rats showed an 83 percent reduction in concussion biomarkers, he said. Human trials are starting soon.

“I think we’re on to something very exciting,” Myer said.

The head as a weapon

Myer is pushing for a “paradigm shift” in concussion research away from focusing on building better helmets to preventing concussions before they happen.

Ever since the NFL first implemented helmets in 1943, researchers have explored ways to make them better, often by adding weight or padding.

John Barresse, a certified athletic trainer at the The Center in Bend, said helmets have gotten better over the years, but that’s not necessarily a good thing. Back when he played high school football in the late 1990s, he learned quickly not to lead with his head during plays because the helmets didn’t have as much padding and, consequently, the hits hurt.

Nowadays, helmets are so comfortable kids can put their heads wherever they want and feel nothing, Barresse said.

Leading with the head rather than the shoulders while tackling causes direct impact to the head rather than letting the body absorb the force of a blow.

“I think we’re making our helmets a little too comfortable and allowing our athletes to start using them as a weapon,” he said.

Helmets’ original purpose was not to prevent concussions but to prevent skull fractures and lacerations to the face. Before football players wore helmets, a few would die every year from blood clots that followed skull fractures, Harbaugh said. So while they’re effective at preventing things like that, they don’t do much to prevent concussions, he said.

In fact, Harbaugh agreed with Barresse that they actually increase one’s likelihood of sustaining a concussion.

“You think about if someone puts a helmet on, especially a helmet with a face mask, that player feels invincible,” Harbaugh said. “They can’t be hurt. And they use their head as a weapon.”

The NFL reported its players sustained 13 percent fewer concussions from 2012 to 2013 due in part to rule changes that discouraged striking with helmets. A rule that took effect in early 2013 banned using the crown of the helmet to hit another player.

Harbaugh, president-elect of the American Association of Neurological Surgeons, said he thinks removing face masks would reduce concussions because players would be less likely to lead with their heads if doing so put their faces at risk.

The other problem: obesity

In the same way that higher altitude increases the brain’s snugness inside the skull by increasing blood flow to the brain, consuming caffeine and taking in supplemental oxygen have the opposite effect, Myer said. He says athletes should not drink energy drinks before games or practices, nor should they take in oxygen from a machine, which is sometimes done on the sidelines in high-altitude cities like Denver.

Water should be the preferred pregame performance drink, especially among younger athletes, whose brains may still be developing and thus more vulnerable to damage, Myer said. Caffeine also can reduce muscle strength through dehydration and can cause delayed gastric emptying, a disorder that slows the process of food exiting the stomach, causing acid reflux, stomach pain or bloating, he said.

A caveat of Myer’s research is that the brains of people who live at high altitudes such as here in Bend, may be acclimated to the elevation and thus those people wouldn’t experience the same benefits during practice or performances.

“That’s something we really need to explore,” he said.

Experts agree that the bigger problem overshadowing the concussion crisis in the U.S. is obesity. If the continued reports of the damage caused by concussions prompt parents to forbid their kids from playing sports, that’s an even bigger problem, Myer said.

“What I’m really worried about is the long-term implications of this concussion crisis and the lower opportunities it might cause for young kids,” he said. “We know the obesity epidemic in the U.S. is growing. Balls and games are the only way kids spontaneously get active. We have to maintain these opportunities for kids and make sports safe.”

— Reporter: 541-383-0304,

tbannow@bendbulletin.com