title: Injuries affect team performance negatively in professional football: an 11-year follow-up of the UEFA Champions League injury study.
abstract: BACKGROUND
  The influence of injuries on team performance in football has only been scarcely investigated.
  
  
  OBJECTIVE
  To study the association between injury rates and team performance in the domestic league play, and in European cups, in male professional football.
  
  
  METHODS
  24 football teams from nine European countries were followed prospectively for 11 seasons (2001-2012), including 155 team-seasons. Individual training and match exposure and time-loss injuries were registered. To analyse the effect of injury rates on performance, a Generalised Estimating Equation was used to fit a linear regression on team-level data. Each team's season injury rate and performance were evaluated using its own preceding season data for comparison in the analyses.
  
  
  RESULTS
  7792 injuries were reported during 1 026 104 exposure hours. The total injury incidence was 7.7 injuries/1000 h, injury burden 130 injury days lost/1000 h and player match availability 86%. Lower injury burden (p=0.011) and higher match availability (p=0.031) were associated with higher final league ranking. Similarly, lower injury incidence (p=0.035), lower injury burden (p<0.001) and higher match availability (p<0.001) were associated with increased points per league match. Finally, lower injury burden (p=0.043) and higher match availability (p=0.048) were associated with an increase in the Union of European Football Association (UEFA) Season Club Coefficient, reflecting success in the UEFA Champions League or Europa League.
  
  
  CONCLUSIONS
  Injuries had a significant influence on performance in the league play and in European cups in male professional football. The findings stress the importance of injury prevention to increase a team's chances of success.
authors: Division of Physiotherapy, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. martin.hagglund@liu.se
authors: Martin
authors: M
authors: Hägglund
authors: Markus
authors: M
authors: Waldén
authors: Henrik
authors: H
authors: Magnusson
authors: Karolina
authors: K
authors: Kristenson
authors: Håkan
authors: H
authors: Bengtsson
authors: Jan
authors: J
authors: Ekstrand
mesh_terms: D000041:Absenteeism; D001265:Athletic Injuries / Q000453:epidemiology / Q000503:physiopathology; D054874:Athletic Performance / Q000502:physiology*; D005060:Europe / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D011446:Prospective Studies; D012916:Soccer / Q000293:injuries* / Q000502:physiology / Q000706:statistics & numerical data
keywords: Elite performance; Epidemiology; Injury Prevention; Soccer; Sporting injuries