title: Exercises to prevent lower limb injuries in youth sports: cluster randomised controlled trial.
abstract: OBJECTIVE
  To investigate the effect of a structured warm-up programme designed to reduce the incidence of knee and ankle injuries in young people participating in sports.
  
  
  METHODS
  Cluster randomised controlled trial with clubs as the unit of randomisation.
  
  
  METHODS
  120 team handball clubs from central and eastern Norway (61 clubs in the intervention group, 59 in the control group) followed for one league season (eight months).
  
  
  METHODS
  1837 players aged 15-17 years; 958 players (808 female and 150 male) in the intervention group; 879 players (778 female and 101 male) in the control group.
  
  
  METHODS
  A structured warm-up programme to improve running, cutting, and landing technique as well as neuromuscular control, balance, and strength.
  
  
  METHODS
  The rate of acute injuries to the knee or ankle.
  
  
  RESULTS
  During the season, 129 acute knee or ankle injuries occurred, 81 injuries in the control group (0.9 (SE 0.09) injuries per 1000 player hours; 0.3 (SE 0.17) in training v 5.3 (SE 0.06) during matches) and 48 injuries in the intervention group (0.5 (SE 0.11) injuries per 1000 player hours; 0.2 (SE 0.18) in training v 2.5 (SE 0.06) during matches). Fewer injured players were in the intervention group than in the control group (46 (4.8%) v (76 (8.6%); relative risk intervention group v control group 0.53, 95% confidence interval 0.35 to 0.81).
  
  
  CONCLUSIONS
  A structured programme of warm-up exercises can prevent knee and ankle injuries in young people playing sports. Preventive training should therefore be introduced as an integral part of youth sports programmes.
authors.affiliation: Oslo Sports Trauma Research Center, Norwegian University of Sport and Physical Education, 0806 Oslo, Norway. odd-egil.olsen@nih.no
authors.forename: Odd-Egil
authors.initials: OE
authors.lastname: Olsen
authors.forename: Grethe
authors.initials: G
authors.lastname: Myklebust
authors.forename: Lars
authors.initials: L
authors.lastname: Engebretsen
authors.forename: Ingar
authors.initials: I
authors.lastname: Holme
authors.forename: Roald
authors.initials: R
authors.lastname: Bahr
mesh_terms: D000293:Adolescent; D016512:Ankle Injuries / Q000517:prevention & control*; D001265:Athletic Injuries / Q000517:prevention & control*; D016000:Cluster Analysis; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000517:prevention & control*; D008297:Male; D016896:Treatment Outcome