What Do We Know about Heading and Concussions?

In soccer, athletes frequently use their heads to connect with the ball. But researchers have raised concerns about the potential risk of concussion from heading the soccer ball. As the World Cup enthralls soccer fans from around the globe, how concerned should we be about heading?

The CUIMC Newsroom interviewed James Noble, MD, a neurologist who studies concussion risk in athletes, about what the research says—and doesn’t say—about the dangers of heading in soccer.

Q: What is it about heading a soccer ball that could be dangerous for the brain?

Researchers have been asking if heading itself—the impact from the ball making contact with the head—is dangerous for the brain or if the real danger comes from the accidental collision of two athletes who are trying to head the same ball. It’s probably both. Other factors, such as age, size, gender, and aggressiveness of play, could influence concussion risk. Researchers need to determine if there’s something specific to younger athletes or professional athletes that may incur different levels of risk.

Q: How do researchers study this issue?

Some approaches assess an athlete’s exposure to head impacts. Studies have used accelerometers that are embedded in helmets, headbands, and mouth guards. These tools measure movement, which is a proxy for the force of an impact, though they don’t measure how the brain responds to that impact.

A number of tests can be performed on the sidelines to get a better idea of the effect of head impacts. Doctors can do a neurological exam to look for signs of concussion. MRI and other specialized scans can look for physical evidence of brain trauma. EEG can identify brain wave patterns associated with concussion.

But athletes often don’t speak up when they’ve been injured. So the real challenge lies in identifying the athlete who needs to be evaluated to determine the impact on the brain. I’m currently developing a helmet that’s embedded with miniaturized EEG technology to send a signal to the sidelines, in real time, when an athlete has a concussion. The technology could be adapted for non-helmeted sports, including soccer.

Q: Should we only be concerned about concussions? Is heading risky even without concussion?

We think that the subconcussive injuries—brain injuries without obvious signs or symptoms—that accumulate over an athlete’s career may be more important in terms of brain injury. Concussions may just be the tip of the iceberg.

Q: Your research suggests that female athletes are at increased risk for concussion compared with males. Is this also true for female soccer players?

At Columbia, we looked at the risk of brain injury in college athletes, men and women, in all contact sports—not just soccer. There are two collegiate consortia now studying sport-specific concussions in female athletes. So far, research suggests that female athletes have similar or higher risk for concussion compared with male athletes, especially at the college level.

Q: Recent lawsuits against FIFA, US Soccer, and the American Youth Soccer Organization call for age limits on heading the ball. What are some of the possible age-related risks related to concussion in soccer?

Age-related risks could be related to brain maturity and response to injury, whether or not an athlete reports a suspected concussion, body development, pre-existing medical problems, and even genetic risk factors. There are so many connected factors here that still need to be sorted out.

Q: Do we know enough about the effects of heading to ban it?

I don’t think so, since a lot remains uncertain, and a call to ban something in organized sports requires a lot of clear and convincing evidence to make the case. Certainly it’s important to avoid head injury in any sport, and we think this is going to turn out to be especially critical for youth athletes. The movement to avoid heading, including heading drills, until the teen years is a good first move until the risks are clear. But while we are just starting to understand the short- and long-term risks of head impacts and subconcussive injuries in other sports, we don’t know the long-term outcomes of heading specifically, or if there’s a threshold age and number of headers—per day, week, season, or career—that we need to be concerned about.

If league organizers, parents, coaches, players, and researchers work together, we could answer these questions. As a field, we’re working towards developing sport-specific and age-specific policies that better protect athletes.

Being athletic has a range of health and social benefits that can last a lifetime. The goal isn’t to steer athletes away from participating in sports like soccer; instead, we should use evidence of the near- and long-term risks to help athletes play safely. This is particularly true for youth athletes, who can’t make decisions for themselves about how they should play or how the game is played. Helmets aren’t the answer, since there’s no completely concussion-proof helmet or headgear. But we can prepare athletes for heading—or avoiding heading—with education and physical training.