Female athletes are 4-6 times more likely to suffer ACL injury than males in comparative sports. A link between landing biomechanics and ACL injury has led to the development of injury prevention focused training protocols. Often the most difficult component of these programs is measuring their effectiveness on factors associated with ACL injury. PURPOSE: The purpose of this study was to test the effects of pre-season and in-season neuromuscular training (NMT) on a field based evaluation used to identify athletes at risk for an ACL injury. The hypothesis was that both in-season and pre-season training would demonstrate improved Tuck Jump Assessment (TJA) score relative to the control group. METHODS: 65 female soccer players were tested in one of 3 groups (pre-season NMT, in-season NMT, control). Participants were filmed with digital video cameras performing TJA and scored at a later date by separate raters. NMT groups received NMT that was synthesized from protocols that reduced ACL injury risk. A mixed design (2X2; group by time) repeated measures ANOVA was employed to test the interaction and main effects of group (ACL intervention in-season NMT vs standard soccer training) and time (pre-season vs post-season) on TJA scores. One way ANOVA compared post-training/season TJA scores between pre-season vs in-season NMT vs standard soccer training. RESULTS: Groups were similar in age height and mass (p>0.05) For the athletes measured pre- and post-season there was a significant main effect of training on the tuck jump assessment score (p = 0.04). The in-season trained group reduced their measured landing and jumping deficits at preseason 5.4 ± 1.6 points to 4.9 ± 1.0 points. Athletes who performed standard soccer training also showed 14% reduction in tuck jump assessment deficit points. No training status (in-season ACL intervention training vs standard in-season soccer) interaction was observed between study groups. However, a main effect of study group was observed between pre-season vs in-season vs untrained groups. Post hoc tests indicated that intensive pre-season training reduced scored deficits greater than either in-season training or standard soccer training. The pre-season ACL intervention resulted in a 1.4 (95% CI 0.6 to 2.2; p = 0.001) point reduction compared to standard soccer training. In-season training reduced by 1.4 (95% CI 0.5 to 2.3; p = 0.003) points compared to in-season ACL intervention. CONCLUSIONS: ACL intervention training can reduce deficits during the tuck jump assessment and may help reduce risk of ACL injury. There may be a dose-response relationship to the neuromuscular training targeted to prevent ACL injury. Future research is warranted to determine if pre-season combined with in-season maintenance training is optimal to improve biomechanics and reduce ACL injury risk. PRACTICAL APPLICATIONS: Pre-season neuromuscular training should be utilized to help minimize the risk factors associated with ACL injury. Progress of the training can be evaluated using a field based Tuck Jump Assessment that is feasible for coaches. Acknowledgements: The authors would like to acknowledge funding support from National Institutes of Health Grants R01-AR049735 and R01-AR055563.
© 2011 National Strength and Conditioning Association