title: Incidence of injury among adolescent soccer players: a comparative study of artificial and natural grass turfs.
abstract: OBJECTIVE
  To investigate the incidence of acute injuries and soccer-related chronic pain from long-term training and during matches in adolescent players using natural grass turfs (NT) and artificial turfs (AT).
  
  
  METHODS
  Case-controlled prospective study.
  
  
  METHODS
  Institutional-level Fédération Internationale de Football Association Medical Centre of Excellence.
  
  
  METHODS
  Youth soccer players (12-17 years of age) from 6 teams, with a predominant tendency to train on either NT or AT, were included. Of 332 players enrolled in this study, 301 remained to completion.
  
  
  METHODS
  Medically diagnosed acute injuries and chronic pain were recorded daily by team health care staff throughout 2005, and reports were provided monthly to the authors.
  
  
  METHODS
  Noninvasive prospective study.
  
  
  METHODS
  Age and turf type.
  
  
  METHODS
  Acute injuries per 1000 player hours on each surface and chronic complaints per 1000 player hours were evaluated according to frequency of surface used > or = 80% of the time. Incidence rate ratio (IRR) of acute injuries and chronic complaints during play on NT and AT was calculated.
  
  
  RESULTS
  There was no significant difference in the incidence of acute injuries between the 2 surfaces during training and competition. However, the AT group showed a significantly higher incidence of low back pain during training (IRR, 1.62; 95% confidence interval, 1.06-2.48). Early adolescence and prolonged training hours were factors associated with an increased incidence of chronic pain in the AT group.
  
  
  CONCLUSIONS
  Adolescent players routinely training on AT for prolonged periods should be carefully monitored, even on AT conforming to new standards.
authors.affiliation: Department of Orthopaedic Surgery, St. Marianna University School of Medicine,2-16-1, Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511, Japan. h2aoki@marianna-u.ac.jp
authors.forename: Haruhito
authors.initials: H
authors.lastname: Aoki
authors.forename: Terushige
authors.initials: T
authors.lastname: Kohno
authors.forename: Hiroto
authors.initials: H
authors.lastname: Fujiya
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Kato
authors.forename: Kanaka
authors.initials: K
authors.lastname: Yatabe
authors.forename: Tsuguo
authors.initials: T
authors.lastname: Morikawa
authors.forename: Jun
authors.initials: J
authors.lastname: Seki
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D001265:Athletic Injuries / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D002648:Child; D002908:Chronic Disease; D016001:Confidence Intervals; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D010146:Pain / Q000453:epidemiology* / Q000209:etiology; D006109:Poaceae; D011446:Prospective Studies; D012307:Risk Factors; D012916:Soccer / Q000293:injuries*