title: Concussed athletes are more prone to injury both before and after their index concussion: a data base analysis of 699 concussed contact sports athletes.
abstract: 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.
authors.affiliation: Department of Surgical and Perioperative Sciences , Umeå University , Umeå , Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Burman
authors.affiliation: Department of Surgical and Perioperative Sciences, Centre of Registries North Sweden, Umeå, Sweden; Department of Epidemiology and Global Health, Umeå University, Umeå, Sweden.
authors.forename: Jack
authors.initials: J
authors.lastname: Lysholm
authors.affiliation: Department of Clinical Neurochemistry Laboratory , Sahlgrenska University Hospital , Mölndal , Sweden.
authors.forename: Pashtun
authors.initials: P
authors.lastname: Shahim
authors.affiliation: Department of Sports Medicine, Department of Community Medicine and Rehabilitation , Umeå University , Umeå , Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Malm
authors.affiliation: Department of Health Sciences , Luleå University of Technology , Luleå , Sweden.
authors.forename: Yelverton
authors.initials: Y
authors.lastname: Tegner
keywords: Concussion; Injury; Sport