The Influence of Age on the Effectiveness of Neuromuscular Training to Reduce Anterior Cruciate Ligament Injury in Female Athletes: A Meta-Analysis
Gregory D. Myer, PhD, FACSM, CSCS, Dai Sugimoto, MS, ATC, CSCS, Staci Thomas, and Timothy E. Hewett, PhD; Am J Sports Med. 2012 Oct 9. [Epub ahead of print]
Anterior cruciate ligament (ACL) injuries early in life may not only have an immediate impact on an athlete’s career but may also have longstanding effects well beyond the years of active athletic participation. The best way to prevent these long-term consequences is to avoid ACL injuries. Currently neuromuscular training (NMT) programs are the focus of ongoing research to determine their effectiveness in preventing ACL injuries. Some investigators theorize that there may be an optimal age to initiate NMT among young female athletes; however, this has yet to be evaluated. With this meta-analysis the authors assessed the influence of age at the time of implementing NMT on the effectiveness of NMT to reduce the risk of ACL injuries. They hypothesized that NMT is more effective in younger populations. Of the available literature, the authors identified 14 studies that met the inclusion criteria. They then extracted data regarding the number of ACL injuries, contact or non-contact mechanism of injury, number of athletes, and age of the participants. The meta-analysis of these 14 studies showed that NMT reduced the odds of knee injuries among female athletes compared to those in control groups (odds ratio = 0.54). NMT participants < 18 years of age reduced their risk of knee injury by 72% compared to controls but the >18 years of age group did not experience a similar benefit. Finally, the authors divided the study population into mid-teens (14-18 years), late teens (18-20 years), and early adults (over 20 years). Meta-analysis of these groups indicated a greater reduction of knee injury risk in the mid-teen category (72% reduction) when compared to late teens who had a trend for less knee injuries (52% reduction) and early adults, who had no reduction in knee injury risk.
The results of Myer’s study suggest that integrated NMT programs have the greatest effect in reducing ACL injuries when initiated between 14 and 18 years of age. The authors provide two possible explanations for this result: (1) greater motivation/compliance of younger athletes and (2) the influence of changes in the musculoskeletal system and hormonal changes in the postpubertal athlete. Further explanations for these results could be that younger athletes have less bad movement habits and can adapt their neuromuscular control better than older athletes. The findings of this study were also echoed by Feigenbaum, who looked at seven year old students who participated in an integrative NMT program. The results support that initiating NMT programs at a younger age is beneficial in injury prevention during adolescence. More research is needed to address the durability of NMT program participation; i.e. is the program effective long after the NMT program is discontinued? Do you incorporate an NMT program in the conditioning programs for your female athletes?
Written by Christian Glaser, DO, and Marc Harwood, MD
Reviewed by: Jeffrey Driban
Related Posts:Myer GD, Sugimoto D, Thomas S, & Hewett TE (2012). The Influence of Age on the Effectiveness of Neuromuscular Training to Reduce Anterior Cruciate Ligament Injury in Female Athletes: A Meta-Analysis. The American Journal of Sports Medicine PMID: 23048042