Concussion prevention: Sorting through the science to see what’s sound

As his helmet collided violently with his opponent’s shoulder, Luke Kuechly looked like a life-size bobblehead doll. In an instant, the Carolina Panthers star linebacker suffered yet another concussion. His season, and perhaps career, was in jeopardy.

A few weeks earlier, Kuechly began wearing an experimental collar around his neck designed to protect his brain from within. The device, known as the Q-Collar and previously sold as NeuroShield, is designed to mimic the woodpecker’s method of injury protection by keeping more blood inside the skull to create a “bubble wrap” effect around the brain.

So, why didn’t this nature-inspired safety equipment avert Luke Kuechly’s 2017 concussion, which apparently he still wears?

As a physiologist and sports medicine researcher, I study how the body responds to exercise and other stressors. I also study ways to prevent and treat sports injuries. As the public learns more about the potential long-term dangers of contact sports, including chronic traumatic encephalopathy (CTE), parents, athletes and sports organizations are desperate to find a quick fix to the concussion crisis. Unfortunately, I do not think there is an easy solution to make inherently high-risk sports safe.

The high altitude argument

Back in 2014, a friend told me about a study which reported that NFL players were 20-30 percent less likely to sustain a concussion in games played at “higher” altitudes. The researchers theorized that higher altitude caused a slight swelling in the brain, and consequently increased brain volume.

This “tighter fit” inside the skull would reduce brain “slosh” during impacts to reduce the likelihood of concussions. Since higher altitude seemed to protect the brain, they argued, it would be beneficial to replicate this “tighter fit.” The authors proposed this could be achieved by applying slight pressure on the neck’s jugular veins to trap a bit more blood inside the brain. A few years earlier, a member of their research team filed a patent for such a device – a jugular compression collar.

While those less familiar with physiology may have been persuaded by this fascinating-sounding explanation, my fellow researcher, Gerald Zavorsky, and I thought this idea was scientifically implausible. Most importantly, the study defined “higher altitude” as anything above a meager 600 feet above sea level – way too low to have any effect on brain volume. Essentially, our brain volume stays remarkably constant at high altitude, even when we may feel short of breath or lightheaded. In the “Mile High City” of Denver, which houses the highest NFL stadium in the country at 5,280 feet above sea level, you would be hard-pressed to experience even a miniscule swelling in the brain. However, at much higher elevations, there is actually an increased likelihood for brain swelling which causes a life-threatening emergency called high altitude cerebral edema.

A game of chance

If altitude does not cause a protective increase in brain volume, then why were concussions reduced in NFL games played at greater than 600 feet above sea level? To answer this question, we examined the same publicly available NFL data set. The original study looked at data from two combined seasons (2012 and 2013), but we analyzed a few additional years. We confirmed that concussion rate was indeed statistically reduced at “higher” altitudes during the 2013 season, but not in the 2012 season. We dug deeper and found no connection between altitude and concussions in the 2014 or 2015 seasons. A separate study in college athletes showed concussions were even more likely at “higher” altitude.

Since the effect wasn’t consistent and repeatability is a major problem in all of science, we suspected the original linkages were due to random chance – a mathematical artifact of using a huge data set of nearly 1500 gridiron giants literally butting heads with one another on a weekly basis. If that was the case, we might expect that something completely arbitrary to also be associated with a reduced risk of concussion. And, indeed our analysis demonstrated that is true. It turns out that NFL teams with animal logos, such as the Miami Dolphins, also had a 20-30 percent reduced risk of concussion compared to teams without animal logos, such as the Pittsburgh Steelers, regardless of game altitude.

Based on our analysis, we concluded that random chance, not physiological response, explains why concussions were less likely at altitudes above 600 feet. Thus, an altitude-mimicking collar seems unjustified for preventing concussions.

The woodpecker theory

A collar based on how woodpeckers keep from hurting their brains is being used by some football players. Piotr Krzeslak/
Supposedly, the Q-Collar also replicates how woodpeckers naturally protect themselves from headaches. According to company information, woodpeckers compress their jugular vein using their neck muscles to induce “tighter fit” and reduce brain “slosh.” While this amazing-sounding mechanism is often presented as a fact, it does not seem to be mentioned anywhere in over a century of scientific studies examining woodpeckers.