Background Ice hockey and football players suffering concussions might have an increased risk for injuries afterwards. We aimed to investigate if concussions predisposed athletes for subsequent sport injuries.

Methods Patient data were obtained from a data base established at the University Hospital in Umea, Sweden. Athletes who had suffered a concussion were included if they had been aged between 15 and 35 years of age, and played ice hockey, football (soccer), floorball and handball. They were studied in terms of all new or previous injuries during 24 months before and after their concussion. Results were compared with a control group of athletes from the same four sports with an ankle injury.

Results Athletes with a concussion were more likely to sustain injuries compared with the control group, both before (OR 1.98. 95% CI 1.45 to 2.72) and after the concussion (OR 1.72. 95% CI 1.26 to 2.37). No increase in frequency of injury was found after a concussion compared with before. This was true for athletes in all four sports and for both sexes.

Conclusions This study indicates that athletes sustaining a concussion may have a more aggressive or risk-taking style of play than their counterparts. Our data do not suggest that a concussion injury, per se, leads to subsequent injuries.