Analysis heads off worries about soccer

While most soccer players, coaches and fans know that heading is an important weapon in any player’s arsenal, parents remain concerned about safety issues and the possible negative effects associated with striking the ball with one’s head.

A recent study by a team of UD researchers has found that heading by female high school and collegiate soccer players does not produce harmful effects in short-term neurocognitive function.

“For several years now, soccer heading has gotten a bad rap as potentially being detrimental to brain function,” says Thomas W. Kaminski, associate professor of health, nutrition and exercise sciences and a co-author of the study. “Because heading is such an important part of the soccer match, further studies examining the influence of this aspect of the game were warranted.”

The study, which appeared in the Journal of Clinical and Experimental Neuropsychology, was titled “Purposeful Heading During a Season Does Not Influence Cognitive Function or Balance in Female Soccer Players.” In addition to Kaminski, it was written by Joseph Glutting, professor of education at UD; April M. Wikstrom, a physician’s assistant with Associated Orthopedic Specialists in Ocala, Fla.; and Gregory M. Gutierrez, a doctoral candidate in UD’s biomechanics and movement program.

Kaminski says the biggest problem with some earlier studies reporting on purposeful heading in soccer was that they often were based on anecdotal accounts.

“Ours is the first study to document heading exposures in both collegiate and high school female soccer players,” he says. “It indicates that, at least in the short term, there appear to be no deleterious effects on neurocognitive function.”

The research team’s results were based on a battery of neuropsychological and balance tests given before and after the soccer season to 71 female participants ranging in age from 14-24. Study participants included both high school and collegiate soccer players.

In a modified Romberg test, which is used as a measure of postural stability, participants were asked to stand on one leg—the leg they used to kick the ball—for 30 seconds per trial, with a 30-second practice trial preceding each test variation. Participants performed two trials of each of the four variations of the test in random order. The report noted that the total number of errors in all eight trials was recorded and used in the analysis.

“Because balance is affected in a typical head injury, this is a good test to use,” Kaminski says. “If soccer heading is bad, this is the test that will show it.”

According to the published study, another measure, known as the Wechsler Digit Span test, was used to assess the players’ concentration and immediate memory recall. That test required participants to repeat, first in forward order and then in reverse, a list of numbers that increased in length.

Also used was the Hopkins Verbal Learning Test to measure verbal memory, with participants being asked to repeat and recognize certain words from a list containing 12 words.

“For the high school players, we used laptops that we took to their respective schools,” Kaminski says. “The athletes enjoyed taking the tests, because they knew it was for the benefit of the game.”
He notes that he was not necessarily surprised by the findings.

“There is a controlled soccer environment that produces players who know how to head the ball,” Kaminski says. “If heading is done properly, there are no bad results.”

Heading is not that much of an issue for younger players, because the ball is mostly kept on the ground at that age level, he says,

“As players grow older, around ages 9-10, they begin to learn how to head a ball,” he says. “Most players know when they are ready to start heading, which is usually anywhere from ages 12-14.”
The report is valuable, because such studies on these groups had not been done before, Kaminski says, adding that he believes it is important for the public to know the research results.

“We were the first to document and use the neurological guidelines required by the Fédération Internationale de Football Association,” he says. “It is all about the preservation of the game, and our data shows that heading is a pretty safe event.”

The results also suggest the need for further study, he says, because any long-term negative effects of heading are not likely apparent through the course of a single season.

“We have to continue to collect data on players through the years to monitor the long-term effects of heading in soccer,” Kaminski says. “Ideally, we would track students through four years of high school and hopefully, in some cases, through four years of college.” At present, the research team is utilizing soccer players from several Wilmington, Del., area schools, including A.I. du Pont and St. Mark’s high schools and Wilmington Friends School, as well as intercollegiate players at UD.

Glutting, who performed the statistical analyses of the test results, says it was interesting being involved in this type of research project, particularly because the subject matter is understandable and easily related to real situations.

“This was my first study on the topic, and I had a great time,” he says.

—Jerry Rhodes, AS ’04