A randomized controlled trial to prevent noncontact anterior cruciate ligament injury in female collegiate soccer players.

BACKGROUND Neuromuscular and proprioceptive training programs can decrease noncontact anterior cruciate ligament injuries; however, they may be difficult to implement within an entire team or the community at large. HYPOTHESIS A simple on-field alternative warm-up program can reduce noncontact ACL injuries. STUDY DESIGN Randomized controlled trial (clustered); Level of evidence, 1. METHODS Participating National Collegiate Athletic Association Division I women's soccer teams were assigned randomly to intervention or control groups. Intervention teams were asked to perform the program 3 times per week during the fall 2002 season. All teams reported athletes' participation in games and practices and any knee injuries. Injury rates were calculated based on athlete exposures, expressed as rate per 1000 athlete exposures. A z statistic was used for rate ratio comparisons. RESULTS Sixty-one teams with 1435 athletes completed the study (852 control athletes; 583 intervention). The overall anterior cruciate ligament injury rate among intervention athletes was 1.7 times less than in control athletes (0.199 vs 0.340; P = .198; 41% decrease). Noncontact anterior cruciate ligament injury rate among intervention athletes was 3.3 times less than in control athletes (0.057 vs 0.189; P = .066; 70% decrease). No anterior cruciate ligament injuries occurred among intervention athletes during practice versus 6 among control athletes (P = .014). Game-related noncontact anterior cruciate ligament injury rates in intervention athletes were reduced by more than half (0.233 vs 0.564; P = .218). Intervention athletes with a history of anterior cruciate ligament injury were significantly less likely to suffer another anterior cruciate ligament injury compared with control athletes with a similar history (P = .046 for noncontact injuries). CONCLUSION This program, which focuses on neuromuscular control, appears to reduce the risk of anterior cruciate ligament injuries in collegiate female soccer players, especially those with a history of anterior cruciate ligament injury.