NEW YORK (Reuters Health) - Professional soccer players who sustain a concussion are more likely to suffer another injury over the next year than players with other injuries, like groin strains or hamstring pulls, according to a new study from Sweden.
Researchers used data from the ongoing Union of European Football Associations (UEFA) Champions League injury study. Participants included 46 all-male pro soccer teams at the highest level of the sport in 10 countries.
Between 2001 and 2012, 1,665 players sustained more than 8,000 injuries. Sixty-six players sustained at least one concussion, the teams reported.
Players who had a concussion tended to also sustain more injuries in general, before and after their head injury, than players who did not, the authors found.
In the year following the concussion, these players were 50 percent more likely to sustain another injury than players who had hurt themselves another way, the authors report in the British Journal of Sports Medicine.
“Compared to the year before, they have doubled the risk of getting any acute injuries the year following a concussion,” lead author Dr. Anna Nordstrom told Reuters Health by phone.
She worked on the study in the department of surgical and perioperative sciences in sports medicine at Umea University in Sweden.
During recovery from a head injury, reaction times can be slower, and a player who returns to the game before fully recovering may be more vulnerable to another injury, she said.
That reinforces the belief that getting players out of the game after a concussion until they are fully recovered is the best policy, which the U.S. already does a better job of enforcing than most other countries at the professional and the amateur level, Nordstrom said.
“These players that we’ve been looking at in the Champions League, they make somewhere around half a million euros per week, which they lose if they can’t play,” she said.
“It’s a lot of money, so it’s difficult to get them to stay out,” she said.
Since players who had sustained concussions also reportedly had more injuries in general, those players may have a more injury-prone style of play or attitude, she suggested.
But that may not be the only explanation, said Chris Nowinski, co-founder and president of the Sports Legacy Institute in Boston, a non-profit dedicated to reducing sports-related concussions.
“Even five to 10 years ago you might finish the game and not count (a head impact) as a concussion,” he said, calling the decade examined in the study the “dark ages” of concussions in sports.
In this study, concussions were recorded essentially by self report, and the players who are more likely to admit to a concussion may also be more likely to report other injuries, he told Reuters Health by phone.
“Having played with both types of people, there are some people that will tell you when they’re hurt and others will not,” said Nowinski, a former professional wrestler with World Wrestling Entertainment.
The situation may be similar in many pro sports, Nowinski said.
“Sports are sports, and until the last few years the culture has been similar, you play through what you can play through,” he said.
In the UEFA data, concussed players only stayed out an average of 10 days after their injury, he noted, so it’s unlikely that they were physically ‘out of shape’ when they returned, but reaction times and cognition may have been slowed.
“I think it probably needs to now be studied in some of our American sports that are not necessarily soccer to see if the same patterns are seen,” said Dr. Robert C. Cantu, clinical professor in the neurosurgery department and co-director of the Center for the Study of Traumatic Encephalopathy at Boston University School of Medicine.
Cantu is also senior advisor to the National Football League’s Head, Neck and Spine Committee.
Possibly in this European study some players returned to the game before they were recovered. Recovery in the U.S. is defined as a return to symptom levels from before the injury, but that brings up another dilemma researchers still face, Cantu said.
“We know at a point in time when an athlete has gotten over symptoms and their neuro exam is clear, (but) even when somebody has recovered by our standards, abnormalities can still be seen for about a month or two on certain research MRI tools,” Cantu told Reuters Health by phone. “Right now we don’t know what that means, but maybe we should be holding these people out a month or two more.”
This is not the first study to show an increase in musculoskeletal injuries after concussion, but it does confirm those results, he said.
“Concussion recognition is a real problem at the FIFA level because at that level there are guidelines, but they are not mandates, and both players and coaches can override the medical team,” he said. “In this country, players are automatically out.”
SOURCE: bit.ly/1vhxbRP British Journal of Sports Medicine, July 31, 2014.