title: The Nordic Football Injury Audit: higher injury rates for professional football clubs with third-generation artificial turf at their home venue.
abstract: BACKGROUND
  Previously, no difference in acute injury rate has been found when playing football on artificial turf (AT) compared with natural grass (NG).
  
  
  OBJECTIVE
  To compare acute injury rates in professional football played on AT and NG at the individual player level; and to compare, at club level, acute and overuse injury rates between clubs that have AT at their home venue (AT clubs) and clubs that have NG (NG clubs).
  
  
  METHODS
  32 clubs (AT, n=11; NG, n=21) in the male Swedish and Norwegian premier leagues were followed prospectively during the 2010 and 2011 seasons. Injury rate was expressed as the number of time loss injuries/1000 h and compared with rate ratio (RR) and 99% CI.
  
  
  RESULTS
  No statistically significant differences were found in acute injury rates on AT compared with NG during match play (RR 0.98, 99% CI 0.79 to 1.22) or training (RR 1.14, 99% CI 0.86 to 1.50) when analysing at the individual player level. When analysing at the club level, however, AT clubs had a significantly higher acute training injury rate (RR 1.31, 99% CI 1.04 to 1.63) and overuse injury rate (RR 1.38, 99% CI 1.14 to 1.65) compared with NG clubs.
  
  
  CONCLUSIONS
  At the individual player level, no significant differences were found in acute injury rates when playing on AT compared with NG. However, clubs with AT at their home venue had higher rates of acute training injuries and overuse injuries compared with clubs that played home matches on NG.
authors.affiliation: Division of Community Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. karolina.kristensson@liu.se
authors.forename: Karolina
authors.initials: K
authors.lastname: Kristenson
authors.forename: John
authors.initials: J
authors.lastname: Bjørneboe
authors.forename: Markus
authors.initials: M
authors.lastname: Waldén
authors.forename: Thor Einar
authors.initials: TE
authors.lastname: Andersen
authors.forename: Jan
authors.initials: J
authors.lastname: Ekstrand
authors.forename: Martin
authors.initials: M
authors.lastname: Hägglund
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000453:epidemiology; D005430:Floors and Floorcoverings / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008420:Manufactured Materials; D009664:Norway / Q000453:epidemiology; D006109:Poaceae; D011446:Prospective Studies; D012307:Risk Factors; D012916:Soccer / Q000293:injuries*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: Ankle injuries; Epidemiology; Lower extremity injuries; Soccer; Sporting injuries