Researchers at Albert Einstein College of Medicine of Yeshiva University and Montefiore Medical Center, the University Hospital and academic medical center for Einstein, used diffusion tensor imaging, an advanced type of MRI-based imaging technique, as well as cognitive tests, to assess brain function in amateur football players. Their findings indicate the possibility of brain injury from frequently heading the ball.
The study included 38 amateur soccer players with an average age of just over 30, who all played the sport regularly since childhood. They were asked to estimate the number of times they headed the ball during the last year. In soccer you cannot use your hands or lower arms on the ball, so players frequently make contact with high balls using their heads to redirect it to another player.
The researchers compared the frequency of headers against the players' brain scans and cognitive function. They found that the players who had headed the ball frequently showed brain injuries not dissimilar to a concussion, known medically as mild traumatic brain injury (TBI).
The findings are of concern - soccer is the world's most popular sport, its fans, followers and players are now growing in numbers in the US; partly thanks to the presence of David Beckham in Los Angeles.
Of the 18 million Americans that play soccer, around three quarters are children. Soccer balls have been measured traveling at speeds of over thirty miles per hour during amateur play, and more than double that in professional games. Moreover, underage players generally use the same footballs as adult players, meaning a young teenage or preteen brain may be more susceptible to injury from the relatively heavier ball impacting the skull. Further analysis revealed a threshold level of approximately 1,000 to 1,500 heads per year. Once players in the study exceeded that number, researchers observed significant injury.
Lead author Michael Lipton, M.D., Ph.D., associate director of Einstein's Gruss Magnetic Resonance Research Center and medical director of MRI services at Montefiore said :
"Our goal was to determine if there is a threshold level for heading frequency that, when surpassed, resulted in detectable brain injury ... While heading a ball 1,000 or 1,500 times a year may seem high to those who don't participate in the sport, it only amounts to a few times a day for a regular player ...
Heading a soccer ball is not an impact of a magnitude that will lacerate nerve fibers in the brain ... But repetitive heading may set off a cascade of responses that can lead to degeneration of brain cells."
In all, five different areas of the brain were seen to be affected - they were clustered in the frontal lobe (behind the forehead) and in the temporal-occipital region (the bottom-rear areas) of the areas that are responsible for attention, memory, executive functioning and higher-order visual functions.
Dr. Lipton and colleague Molly Zimmerman, Ph.D., assistant professor in the Saul R. Korey Department of Neurology at Einstein, also gave the same 38 amateur soccer players tests to assess their neuropsychological function. Players with the highest annual heading frequency performed worse on tests of verbal memory and psychomotor speed (activities that require mind-body coordination, like throwing a ball) relative to players with fewer number of headers.
Diffusion tensor image showing white matter fibers (in blue) that were found to be affected by heading.
Dr. Lipton said :
"These two studies present compelling evidence that brain injury and cognitive impairment can result from heading a soccer ball with high frequency ... These are findings that should be taken into consideration in planning future research to develop approaches to protect soccer players."Heading the ball is such an integral part of the game that it would be impossible to eliminate it, and no soccer fan would want to see that exciting part of the game impinged upon.
Some of the best moments come when a player's head connects with the ball in the goal mouth and scores without using his hands or feet, effectively in one full body movement.
Health care professionals, trainers and coaches could monitor the frequency of potentially harmful actions, especially during practice sessions, and limit exposure according to established thresholds.
Another possibility would be a simple helmet arrangement, especially for underage and amateur players. It wouldn't appear that the soccer superstars have too much to worry about, even if they do suffer mild brain damage, their lifestyles and income potentials are what most of us can only dream of.
Dr. Lipton continued :
"In the past, pitchers in Little League Baseball sustained shoulder injuries at a rate that was alarming ... But ongoing research has helped shape various approaches, including limits on the amount of pitching a child performs, which have substantially reduced the incidence of these injuries."Dr. Lipton concluded :
"Brain injury due to heading in children, if we confirm that it occurs, may not show up on our radar because the impairment will not be immediate and can easily be attributed to other causes like ADHD or learning disabilities ...
We, including the agencies that supervise and encourage soccer play, need to do the further research to precisely define the impact of excessive heading on children and adults in order to develop parameters within which soccer play will be safe over the long term."
Written by Rupert Shepherd