Concussion Linked to Altitude in Athletes: Higher Elevations Mean Fewer Brain Injuries

It turns out that there may be a link between altitude and concussion. Scientists have discovered that high school athletes playing at higher altitudes suffer fewer concussions than those closer to sea-level. The findings reveal a bit more about how pressure can play a role when it comes to the physiological changes in the brain.

The incidence of concussion among high school athletes has grown tremendously over the years. In fact, the Centers for Disease Control and Prevention estimate the annual incidence of sports-related traumatic brain injury in the U.S. to be 1.6 million to 3.8 million with many more going undiagnosed. In a recent 10-year period there has been a 100 percent increase among 8 to 13-year-olds and a 200 percent increase among 14 to 19-year-olds.

In order to learn a bit more about concussion and altitude, the researchers analyzed concussion statistics from athletes playing multiple sports in 497 high schools from across the U.S. with altitudes ranging from 7 feet to 6,903 feet with 600 feet being the median. The scientists also examined football separately since it has the highest concussion rate of high school sports.

So what did they find? It turns out that there was a 31 percent decrease in concussion rates among all high school sports played at altitudes of 600 feet and above. In addition, concussion rates for high school football players at these altitudes decreased by 30 percent.

"This is the first time any research has linked altitude to sports-related concussion," said Dawn Comstock, one of the researchers, in a news release. "It appears that when you are at altitude there may be a little less free space in the skull so the brain can't move around as much."

So what caused the concussion declines? Researchers aren't exactly sure. However, they do have a few theories. As one ascends in altitude, blood vessels in the brain undergo a mild edema or swelling. This swelling along with other physiological changes cause the brain to fit more snugly in the skull, which means that it can't move around as violently when struck. Since sports-related concussions usually result from the brain colliding with the skull following a blow, it would make sense that altitude would play a role.

"If this study is correct, we should look to replicate our findings in the National Football League," said Comstock in a news release. "For example, if the Broncos play the Chargers in San Diego or the Dolphins in Miami they should experience more concussions than when they play here in Denver."

The findings are published in the Orthopaedic Journal of Sports Medicine.