Studying head injuries

High-school athletes playing at elevation suffer far fewer concussions than their sea-level peers, according to an intriguing new Colorado School of Public Health study that could lead to the first innovations in helmet design in decades.

“At higher elevations, your brain swells a bit, so it takes up more room in the skull and there is less room for it to slosh around,” explained concussion researcher Dawn Comstock, Ph.D., an associate professor of epidemiology at the school. The Colorado School of Public Health is a collaboration of the University of Colorado Denver, Colorado State University and the University of Northern Colorado.

The study, published in the Orthopaedic Journal of Sports Medicine in December, is the latest in a series of groundbreaking papers to grow out of Comstock’s National High School Sports Related Injury Surveillance program (RIO) — a massive dataset she developed in 2004 to fill a critical void in understanding how, when, and why high-school sports injuries occur.

“Ten years ago, we knew almost nothing about rates and patterns of injuries in high-school athletes,” she said. That’s a problem, because good data can drive changes in policy and equipment — preventing injury. “When you start to find patterns, you can come up with ways to intervene.”

Today, RIO includes 50,000 detailed injury reports, and is updated weekly by athletic trainers at hundreds of high schools around the country. Mining it, Comstock and other researchers are gaining a greater understanding of sports-related concussions, which occur more than 1.6 million times annually in the United States (one in five among high-school students).

One of Comstock’s recent studies showed that athletes with stronger necks were significantly less likely to suffer concussions during play. Simple neck-strengthening exercises during warm-up might possibly reduce risk, she said. Another study found that choice of helmet — from used, reconditioned helmets to new top-of-the-line options — mattered little when it came to head-injury risk. “Parents may not need to go out and buy the most expensive helmet,” she said.

For the altitude study, co-author David Smith, MD, of Cincinnati Children’s Hospital, reached out to Comstock to explore the theory that altitude-induced brain swelling might actually be protective when it came to concussions. “The completeness of her surveillance system is just stellar,” he said.

The two looked at concussion statistics from 497 high schools across the United States, ranging from 7 to 6,903 feet, with a median elevation of 600 feet. Because football constitutes the bulk of high-school-sports-related concussions, at 47 percent, they examined it separately. Athletes playing any sport above 600 feet showed a 31 percent lower concussion rate. For football, the risk reduction was 30 percent.

Smith is now working to expand the research to the National Football League and hopes to someday develop a device that would mimic the intracranial pressure induced by altitude — reducing concussion risk at any elevation. Already, in one study he conducted in rats, those wearing a neck collar that applied mild pressure to the jugular — thus boosting pressure in the brain — suffered 83 percent fewer concussions when subjected to severe impact than those without the collar.

“It is very early days, but it’s exciting,” Comstock said. “We have not had a new piece of protective equipment come on the market for decades.”