November 29, 2011
Soccer ‘Headers’ Can Lead To Brain Injury
Soccer players beware: Doctors warn that ℠heading´ too many balls can lead to brain damage. That´s the message in a new study from researchers who persented their research at the annual meeting of the Radiological Society of North America.
Using diffusion tensor imaging (DTI) to study the effects of soccer ℠heading,´ researchers have found that players who head the ball very frequently have brain abnormalities similar to those found in traumatic brain injury patients.
The study, presented today at the annual meeting of the Radiological Society of North America (RSNA), found that more than 1,000-1,500 headers per year will likely affect regions of the brain responsible for attention, memory, sight and problem solving.
The team used a magnetic resonance technique on 32 amateur soccer players with an average age of 30.8 years old and had played since childhood. Based on their findings, the team said there seems to be a safe cut off level of 1,000 or fewer headers a year at which no harm will be done, but they believe more research is needed to confirm this.
Heading, in which players field the soccer ball with their head, is an essential part of the game and the focus of many training drills. But the controversial play has been blamed on at least one death: English footballer Jeff Astle.
Astle, 59, who died in 2002, developed cognitive problems after years of playing English football (soccer). The coroner ruled that his death resulted from a degenerative brain disease caused by heading heavy leather footballs.
Lead study researcher, Dr Michael Lipton of Montefiore Medical Center, the university hospital for the Albert Einstein College of Medicine, New York, noted that soccer balls today are much lighter than those used in the mid-60s when Astle was playing, but they still pack a punch.
Kicked footballs are capable of traveling at speeds in excess of 30 miles per hour during recreational play and as much as 65 mph during professional play.
However, some experts have doubted that the force exerted by a ball would be enough to cause damage to the brain.
Dr Andrew Rutherford from the School of Psychology at Keele University has been researching the possible damage caused by heading for several years. He says he is yet to be convinced by the evidence so far. He believes most head trauma seen in football/soccer is due to players clashing heads when they are going for a header, rather than when they make contact with the ball itself.
Lipton agreed that “heading a soccer ball is not an impact of a magnitude that will lacerate nerve fibers in the brain.” But, he did say that “repetitive heading could set off a cascade of responses that can lead to degeneration of brain cells.”
For their study, Lipton´s team estimated how often each of the 32 soccer participants headed the ball on an annual basis and then ranked the players based on heading frequency. They then compared the brain images of the most frequent headers with those of the remaining players and identified the areas of the brain where fractional anisotropy (FA) values differed significantly.
FA -- the measurement of the movement of water molecules along axons -- is measured using DTI, which is good for visualizing nerve brain tissue.
They discovered five regions of the brain that were damaged: areas in the front of the brain and towards the back of the skull where processes like attention, memory, executive functioning and higher-order visual functions take place.
The researchers believe these injuries build up over time.
The team also conducted a separate study with the same players, testing them to assess their neuropsychological function, such as verbal memory and reaction times. Those with the highest annual heading frequency performed worse on tests of verbal memory and psychomotor speed tests, which require hand-eye coordination.
Lipton said the findings were important “given that soccer is the most popular sport worldwide and is played extensively by children.” He added: “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.”
Lipton believes more research is needed on the effects of heading, particularly because if youngsters are being harmed the damage may not be immediately obvious.
“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,” he said.
“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,” he added.
“These are findings that should be taken into consideration in planning future research to develop approaches to protect soccer players,” Lipton said, adding that as there appeared to be a safe range for heading, a more precise number could be calculated and guidelines drawn up.
Such efforts have succeeded in baseball, he noted. “In the past, pitchers in Little League Baseball sustained shoulder injuries at a rate that was alarming,” he explained. “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.”
However, the study findings are not conclusive enough to confirm long-term heading causes brain damage, cautioned Luke Griggs, spokesman for brain injury association Headway.
“The research team only studied 32 amateur players, and we would be very wary of drawing any meaningful conclusions from a study with such a small sample size,” he told the Daily Mail. “In addition, footballs are much lighter today than ever before so any possible risk that may or may not exist is significantly reduced.”
On the Net:
- Radiological Society of North America
- Montefiore Medical Center
- Albert Einstein College of Medicine
- Keele University