Brain Trauma in Sports
Brain trauma in sports is not a new occurrence, and much has been done to improve the safety of contact sports. But recent studies have shown that heading a soccer ball is not as innocuous as once was thought. Headers sometimes result in a concussion, and thousands of headers over a career could lead to permanent brain damage.
In addition, hockey Luddites have traditionally dismissed brain traumas with “don’t worry, it’s only your coconut.” However, even big, tough hockey players, football players, and soccer stars suffer mightily from the result of repetitive head traumas. A recent rash of suicides by ex-players in the National Football and Hockey Leagues, most of whom probably suffered from chronic traumatic encephalopathy (CTE), has again awakened the sports world to the dangers of concussions.1 We are dealt only one brain for a lifetime.
Soccer Players Not Immune
A growing body of evidence points to the adverse toll of multiple headers over the course of one’s career. One study of 19-year-old amateur soccer players revealed serious damage to the white matter in the brain.2 White matter is vital for most of our brain functions. These troubling findings were not found in any of the “control” swimmers who were examined.
Another study concluded that as the number of headers increased, cognitive function (such as memory) declined.3 This study also discovered that with increasing numbers of headers, the brain damage grew more severe. They measured damage by assessing the white matter of the brain. According to the study, participants had headed between 32 and 5,400 times (median 432 times) over the previous year. Heading was associated with lower fractional anisotropy (FA) at 3 locations in temporo-occipital white matter. Lower levels of FA were also associated with poorer memory scores (P<0.00001), with a threshold of 1,800 headings per year.3
The physics and mechanics of headers are complex. A soccer ball weighs about 1 pound, and the speed of a kicked ball may easily exceed 40 miles per hour. Our fluid-filled brains cannot be compressed to any great extent, which limits how much of the blow may be safely absorbed. When struck by a soccer ball, the brain often sustains a significant “G” force. The angle of impact is important, along with the position and acceleration of neck muscles. If the ball is overinflated and wet, a more severe impact can result. Goal kicks will result in a higher “G” force than is encountered from a simple throw-in. Many headers result in no brain damage, while others might disrupt sensitive brain pathways, at least temporarily.
Based upon available evidence, many young soccer players will travel through life with a compromised brain. Thinking, memory, and attention may be diminished. Many years of soccer could lead to an increased chance of developing a devastating neurologic condition. These include amyotrophic lateral sclerosis (ALS), Parkinson disease, and dementia.4 CTE, a familiar condition among professional football players, has been identified in several professional soccer players.
At least 25% of soccer concussions are the result of heading the ball. However, I am equally concerned about the cumulative effects of many “subconcussive” hits throughout a career. Collegiate and professional players may head the ball from 700 to 1,400 (or more) times per season. Over a number of years, some players may have headed the ball more than 8,000 times. When I played soccer in the ‘70s, the season was only 3 months long. Now, with many kids playing soccer 8 months per year, their total number of headers has dramatically increased.
There are multiple factors that determine how one’s brain copes with head trauma. Many football and soccer players suffer long-term consequences, while others remain perfectly fine. The variables include genetics, psychiatric makeup, the position played, total number of blows to the head, strength of the neck muscles, number and severity of concussions, and other factors.
Making the Game Safer: More Research Needed
Further research is necessary. A helpful study would compare soccer players with age-matched “controls” who did not play contact sports. Memory, IQ, and attention testing for the 2 groups, from ages 30 through 80, could reveal major differences. Another helpful study would be to compare the rates of neurologic degenerative conditions in soccer players versus controls, particularly at older ages.
There are interventions that would result in a safer game. Eliminating headers prior to age 12, 13, or 14 would help. Using a lighter ball that is slightly underinflated would minimize the “G” force. Even if the ball weighed 5% less, it would result in a significantly lower impact. Strengthening neck muscles, which absorb much of the blow, would certainly help to prevent injury. Headgear research may lead to a helmet that actually protects the brain. There is scant evidence that the current soccer helmets offer any real benefit. These helmets are being sold with promises that are not backed by data.
As with football, most soccer-related subconcussive brain traumas occur during practice. The number of headers should be minimized. Headers during practice should be low velocity (throw-ins, as opposed to long corner or goalie kicks). The balls used during practice ideally would be smaller, lighter, and underinflated.
Even considering that headers are integral to the game, it would help if we minimized the high-velocity impacts. Goalie punts to midfield result in higher “G” forces. I remember playing midfield in November. The ball was wet and heavy. The goalie would kick it high in the air, sending it crashing down on my head with an enormous force. Players should not be allowed to head the goalie’s punt. This would only marginally affect the game, as midfield play rarely leads to a goal. Players can field a high punt with their chests or feet.
Corner kicks often result in collisions between 2 players’ heads. The ball may travel at a high velocity. In addition, the forward may whip his/her head into the ball, creating an angular acceleration that increases brain trauma. Corner kicks are a vital part of soccer, and cannot be eliminated. However, there may be means by which we can lessen the danger. One possibility is to move the corner kick closer to the goalie box, minimizing the speed of the ball.
Soccer is a wonderful and universal game, accessible and inexpensive. When I played and coached, little thought was given to the cumulative effects from headers. We now realize that years of small blows to the head have consequences. It is probable that many young players progress into adulthood with compromised brains due to soccer. We must do more to protect their brains from long-term damage.