"Hey, Coach! Can we head the soccer ball?" asked one 10-year-old girl during pre-season practice. "If the ball's coming fast, duck. If not, go for it," the coach answered.
While the player's question echoes a hesitation many soccer parents share, the coach's answer reflects the ambivalence surrounding the heading worry.
Is it safe to hit soccer balls with your head? The latest word, according to the nation's top sports concussion experts, is a qualified yes.
The concern and confusion are understandable. In a study that sent shock waves through soccer leagues around the world, European researchers reported in 1999 that years of soccer playing may be associated with reduced cognitive abilities. The study of Dutch amateur and professional soccer players suggested that, when compared with athletes in non-contact sports, the soccer players were, on average, slower at learning and remembering new material.
"The authors generalized that heading was the culprit," said Mickey Collins, assistant director of sports concussion programs at the University of Pittsburgh Medical Center, "but the study wasn't well-controlled for heading. It could have been lifestyle or a number of other factors."
That study prompted American researchers to launch their own investigations, none of which turned up a link between heading and later cognitive problems.
When he heard the results, Kevin Guskiewicz, director of sports medicine research at the University of North Carolina, Chapel Hill, began analyzing data he'd been collecting on the school's athletes.
At the university, every freshman athlete is given a series of mental ability tests, including tests for concentration, mental speed and memory, upon admission. This serves as a baseline in case the player later suffers a head injury. Using this data, Guskiewicz performed a retrospective study. He looked at 91 incoming soccer players and compared them to 96 incoming athletes who had played non-contact sports. He also tested 53 non-athlete students as a second control group.
He found the soccer players to be no different in neuro-cognitive abilities than the two control groups.
"We did see a higher prevalence of concussion among the soccer players, but that made no difference in cognitive ability," Guskiewicz said. His findings were published in the American Journal of Sports Medicine last year.
In addition, researchers at the University of Pennsylvania studied 100 varsity collegiate soccer players before and after the players went through a 20-minute soccer-heading practice session. They found no decrease in mental performance scores after the heading sessions and later published their findings in the Clinical Journal of Sports Medicine.
But couldn't multiple impacts to the head, such as those sustained when repeatedly heading soccer balls, have a degenerative effect on the brain even if they don't cause concussion?
"Current scientific literature refutes that as well," said Guskiewicz, who last year wrote a position paper on the subject for the Department of Health and Human Services. "No published study has provided direct evidence that the practice of heading a soccer ball causes long-term deficits in mental function," he wrote. "Preliminary evidence suggests that if done correctly, heading a soccer ball is safe."
The American Youth Soccer Organization agrees: "We tend to be conservative," said Rick Davis, director of player programs for AYSO, based in Hawthorne, "and our stand is that until there's conclusive information that heading soccer balls is a problem, we allow it." However, he added, "we would never force anyone to do something they didn't feel right about."
AYSO recommends that its coaches not teach heading to kids under age 8, said Davis, "because it's not a necessary part of the game at that level," but suggests they introduce the skill to players age 10 to 12.
Although concussions do occur in soccer, they're unlikely to be the result of heading a ball, Guskiewicz said. Most soccer concussions occur in head-to-head, head-to-ground or head-to-goal-post collisions and rarely in a head-to-ball contact. To put the risk in perspective, 64% of all sports-related concussions among high school boys occur in football, 11% in wrestling, 6% in soccer and 4% in basketball, Collins said.
The worst thing an athlete can do after sustaining a concussion is to go back to play too soon, Collins said. For example, if a soccer player suffers a concussion, returns to play before fully recovered, then heads a soccer ball, serious problems could result.
"Even if the brain is 95% recovered, a minor blow to the head before it's completely healed can result in permanent brain damage and even death," he said. Second impact syndrome, as it's known, is responsible for the deaths of several U.S. high school kids each year.