Researchers looked at the number and cause of concussions reported among soccer players at a sampling of 100 high schools across the U.S. between 2005 and 2014. They calculated that there were 627 concussions among girls and 442 among boys. Most of them were caused by physical contact with another player rather than "heading," or hitting the ball off the head.
The study found that for every 10,000 "athlete exposures" -- a student participating in a soccer game or practice -- there were 4.5 concussions among girls and 2.8 among boys. The study found that the rates of concussions in girls' and boys' high school soccer had risen over the nine-year study period, although the concussion rate during competitive play among girls dropped in the most recent season (2013-2014).
Even though high school football has soccer beat in terms of concussion risk, soccer is still the second leading cause of the head injury among female athletes. For boys, soccer was the fifth leading cause of concussions.
Soccer has widely been regarded as a safer sport for children and teens than football, boxing
or even baseball, but several recent tragedies suggest otherwise.
Curtis Baushke died last year in his early 20s after being knocked unconscious three times in his 14 years of playing soccer, The New York Times reported
. Although his death was attributed to a prescription drug overdose, Baushke suffered migraines and depression following his head injuries. A postmortem examination of his brain revealed signs of chronic traumatic encephalopathy, a degenerative brain disease that has been linked to head injury.
Concussions can cause memory loss, irritability and sleepiness, which were among the most common symptoms found in the current study. These problems can last up to several months. And reports are now starting to trickle in that soccer, like football and boxing, can also lead to lasting brain damage
"There has been a discussion in the soccer world for the last year or so about how to lower the rates of concussions, like in every other sport," Fields said.
What Fields and her colleagues found in the current study suggests that the most effective way to reduce concussions could be to enforce rules against rough play. About 52% of concussions in girls and 69% in boys were because of physical contact between players -- in many cases, elbows and shoulders hitting the head, Fields said.
"If we can enforce the rules and minimize player-to-player contact, that could get rid of 60% of concussions, plus that would reduce other injuries," such as sprained ankles and wrists and torn ligaments, Fields said.
According to FIFA, soccer's governing body that sets the rules for both professional and youth leagues, only shoulder-to-shoulder contact is permitted. However as soccer has grown in popularity in the U.S. in the last several decades, "we've allowed it to become more of a contact sport," Fields said.
, founding executive director of the Sports Legacy Institute
, a nonprofit focused on research and prevention of brain trauma, agrees with the importance of enforcing these rules. "The fastest way to make high school soccer safer is to limit rough play," he said. "Right now, there are potentially more collisions being allowed than should be."
In order to make these changes, Nowinski said, safety needs to be seen as more of a priority in soccer among governing bodies, such as U.S. Soccer and state athletic associations.
A spokesman for US Soccer said they are not commenting on the study or the issue at the time because of current litigation
Although the governing bodies for football, ice hockey and lacrosse have made their sports safer for the brain, both at the professional and youth levels, soccer has lagged behind, he said. "Soccer has been hiding until the spotlight is on them," Nowinski said, who played football for Harvard University in the late 1990s, when it was "fine to shove your helmet into someone else's helmet."
However, it may not be possible for soccer to avoid the spotlight any longer. In the last year and a half, there have been a number of high-profile cases of chronic traumatic encephalopathy among soccer players, including Curtis Baushke, Nowinski said. One of the most recent was Hilderaldo Bellini, a soccer star from Brazil, who was found after his death in 2014 to have sustained this type of brain damage.
"With CTE, you have a picture of a damaged brain and the story of how it destroyed someone's life," said Nowinski, who suffered a concussion in 2013 as a professional wrestler that forced him to retire.
In addition to calling for enforcement of the existing rules, Nowinski and the Sports Legacy Institute are campaigning to ban heading
, at least by players younger than 14.
The current study by Fields and colleagues, as well as previous research, found that this practice is associated with about a third of concussions in high school and among younger players. The current study also found that about 10% of concussions were due to soccer activities such as defending, goaltending and chasing loose balls.
Although heading does not appear to pose as big a concussion risk as rough play, the Sports Legacy Institute supports banning it among younger players for practical reasons. "A lot of people support not hitting children in the head," and there is already support from prominent soccer players, coaches and doctors, Nowinski said. It will be harder to change the soccer culture at the high school level, he added.
Nowinski and Fields agree that it doesn't appear that wearing helmets will be part of the answer to reducing concussions in soccer. Even in football, there are questions about how much helmets have reduced the risk of concussion
, though they have served their purpose to reduce skull fractures. "It actually increases head-to-head contact because people are less careful," Nowinski said.
Soccer players occasionally do wear helmets. Alexandra Popp, goalie for Germany, wore one in the third-place match against England in the recent Women's World Cup, but it was actually to protect her cuts, Fields said.
There are also reports that headbands
, which look not unlike 1980 sweatbands, can reduce the risk of concussions, but the data so far are not convincing, Fields said.
Another concern the current study raised is why girl soccer players had more concussions than boys, which wasn't always the case
. "Initially this was surprising to us," Fields said. Although the reasons for the difference are unclear, it could be because women's necks are thinner and less strong than men's, and thus less able to soften the force of a hit to the head. Another reason might be that women are more likely to report pain and symptoms related to concussions than men are, Fields said.
In her experience, Fields has noticed pushback from soccer leagues at the notion of enforcing rules against rough play and penalizing players for it. "They don't think contact can be ratcheted down. I disagree because I've played (in an amateur soccer league) for 40 years, and I've watched the game change (and) become safer for the lower body," Fields said.
Parents can help ensure their kids play soccer as safely as possible by having their kids play for teams and coaches that encourage technical skills rather than physicality, Fields said. They can find these teams and coaches by talking with other parents and going to see games.