Superior compliance with a neuromuscular training programme is associated with fewer ACL injuries and fewer acute knee injuries in female adolescent football players: secondary analysis of an RCT
Martin Hagglund, Isam Atroshi, Philippe Wagner, Markus Walden. Published Br J Sport Medicine: 2013 Oct; 47(15):974-9. doi: 10.1136/bjsports-2013-092644. Epub 2013 Aug 20
Take Home Message: Neuromuscular training programs have shown to significantly reduce the number of ACL injuries. Previous literature identified that a young starting age has the greatest protective benefit for ACL injuries. This study added to the existing evidence that high compliance with NMT programs is another key factor in reducing ACL injuries.
Neuromuscular training (NMT) has established its role in injury prevention, especially at the knee. It is known that the initiation of NMT at a young age leads to more effective injury prevention; however other factors such as compliance have not had such support in the literature. Therefore, Hagglund et al. investigated compliance with NMT programs as another key element in successful knee injury prevention. Hagglund performed a sub-study of a previously published randomized control trial, which examined the use of NMT programs for the prevention of acute knee injuries in adolescent female soccer players. The end points for Hagglund’s analysis were anterior cruciate ligament (ACL) injury rate for the primary outcome, acute knee injury, and severe knee injury (caused a greater then four week absence). The study population consisted of 2471 athletes in the intervention group and 2085 athletes in the control group. The intervention group was further subdivided into low, intermediate, and high compliance groups based on their completion of NMT sessions per week. Decreasing compliance was observed for the individual player (~ -5% per month) over the course of the season, as well as attendance of practice sessions (~ -2% per month). The decrease in practice attendance rates was most noticed in the intermediate compliance tertile (decrease by 12%) and low compliance tertiles (decrease by 29%), while the high compliance tertile only showed a decrease of 5%. Injury rates showed a significant reduction (88%) in ACL injury between the high compliance and low compliance tertiles of the individual athlete group. The rate reduction of severe or acute knee injuries in the high and intermediate compliance tertiles was between 72% and 90% when compared to the low compliance tertile.
Findings of this study suggest that compliance is another key limiting factor of NMT programs in the prevention of knee injuries. One advantage of such warm-up programs is that it can be implemented and monitored by the coaching staff, which in turn can also pose a problem. The coaching staff at times is only interested in short term success and may place the potential of significant knee injuries second. Adolescent athletes or ones that do not compete on the highest level may not recognize the importance of warm-up programs, and as a result, may not perform them correctly or at all. Hagglund provides a feasible solution to maximizing the exposure to NMT programs, by implementing it for every practice, which guarantees that each athlete is exposed to such warm-up programs. A previous study by Myer concluded that implementation of NMT programs for adolescent female athletes ages 14 to 18 years shows the greatest benefit in ACL injury prevention. Judging by those two studies, age and compliance are important factors for a successful NMT program, however questions for the durability of NMT benefits remains.
Questions for Discussion: How can compliance with NMT programs be increased and maintained over the course of a season? How many NMT sessions per week are necessary to obtain the greatest benefit? How can exposure to NMT programs be increased?
Written by: Christian Glaser, DO
Reviewed by: Stephen Thomas