title: Effect of a novel movement strategy in decreasing ACL risk factors in female adolescent soccer players: a randomized controlled trial.
abstract: OBJECTIVE
  To determine the effect of a novel movement strategy incorporated within a soccer warm-up on biomechanical risk factors for anterior cruciate ligament injury during 3 sport-specific movement tasks.
  
  
  METHODS
  Single-blind, randomized controlled clinical trial.
  
  
  METHODS
  Laboratory setting.
  
  
  METHODS
  Twenty top-tier female teenage soccer players.
  
  
  METHODS
  Subjects were randomized to the Core Position and Control movement strategy (Core-PAC) warm-up or standard warm-up, which took place before their regular soccer practice over a 6-week period. The Core-PAC focuses on getting the centre of mass closer to the plant foot or base of support.
  
  
  METHODS
  Peak knee flexion angle and abduction moments during a side-hop (SH), side-cut, and unanticipated side-cut task after the 6 weeks with (intervention group only) and without a reminder to use the Core-PAC strategy.
  
  
  RESULTS
  The Core-PAC group increased peak flexion angles during the SH task [mean difference = 6.2 degrees; 95% confidence interval (CI), 1.9-10.5 degrees; effect size = 1.01; P = 0.034] after the 6-week warm-up program without a reminder. In addition, the Core-PAC group demonstrated increased knee flexion angles for the side-cut (mean difference = 8.5 degrees; 95% CI, 4.8-12.2 degrees; ES = 2.02; P = 0.001) and SH (mean difference = 10.0 degrees; 95% CI, 5.7-14.3 degrees; ES = 1.66; P = 0.001) task after a reminder. No changes in abduction moments were found.
  
  
  CONCLUSIONS
  The results of this study suggest that the Core-PAC may be one method of modifying high-risk soccer-specific movements and can be implemented within a practical, team-based soccer warm-up. The results should be interpreted with caution because of the small sample size.
authors.affiliation: *Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departments of †Physical Therapy; and ‡Occupational Science and Occupational Therapy, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; §Department of Epidemiology and Preventive Medicine, Monash University, Victoria, Australia; ¶Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatoon, Canada; and ‖Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Celebrini
authors.forename: Janice J
authors.initials: JJ
authors.lastname: Eng
authors.forename: William C
authors.initials: WC
authors.lastname: Miller
authors.forename: Christina L
authors.initials: CL
authors.lastname: Ekegren
authors.forename: James D
authors.initials: JD
authors.lastname: Johnston
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Depew
authors.forename: Donna L
authors.initials: DL
authors.lastname: Macintyre
mesh_terms: D000293:Adolescent; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D012307:Risk Factors; D016037:Single-Blind Method; D012916:Soccer / Q000293:injuries*; D063996:Warm-Up Exercise / Q000502:physiology