Summary

Our systematic review and meta-analysis found that athletes participating in neuromuscular training programs had a 54% reduction in risk of ACL injury, particularly for those over age 18 and with interventions utilizing balance boards.

Abstract

Introduction

Both the medical community and the general public have acknowledged the cost, prevalence, and gravity of anterior cruciate ligament (ACL) ruptures. Approximately 400,000 ACL reconstructions are performed each year in the United States alone. Effective ACL injury prevention programs may be paramount in reducing this significant injury burden.

Objective

To determine the effectiveness of ACL injury prevention programs and generate updated guidelines that can be implemented to protect athletes from these injuries.

Methods

Embase, PubMed, and Ovid (MEDLINE) were searched in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included studies were interventional in nature, focused on ACL injury prevention as opposed to treatment, and provided data on ACL injury rates following intervention implementation. Using random-effects models, the pooled risk ratio (RR) was generated for all data. Sub-analyses were also completed for female-only, high school vs. collegiate/professional, handball, soccer, and balance board data.

Results

A total of 18 articles were identified after review (9 randomized control trials, 9 prospective cohort studies). The 25,166 studied athletes played handball, soccer, basketball, or volleyball (mean age = 19.3, SD = 3.6 years; >85% of players were female). All interventions were studied for a minimum of one season (mean = 1.3, SD = 0.59). Athletes who participated in an ACL injury prevention program were significantly less likely to sustain an ACL rupture with a pooled RR of 0.46 (95% CI, 0.36-0.57; P < 0.01; I2 = 49%; T2 = 0.2500). When analyzed by age, there was a significant risk reduction in ACL rupture for collegiate/professional athletes over age 18 (RR = 0.50; 95% CI, 0.38-0.64; P < 0.01; I2 = 66%; T2 = 0.3489) but no significant change for players under age 18 (RR = 0.35; 95% CI, 0.22-0.55; P = 0.47; I2 = 0%; T2 = 0.0738). Of the 12 studies that included data for female players, the pooled RR was 0.57 and not statistically significant (95% CI, 0.43-0.74; P = 0.13; I2 = 32%; T2 = 0.1487). When assessing the efficacy of ACL injury prevention programs by sport, there was no significant RR for athletes playing soccer (RR = 0.30; 95% CI, 0.19-0.46; P = 0.06; I2 = 47%; T2 = 0.4734) or handball (RR = 0.66; 95% CI, 0.46-0.96; P = 0.38; I2 = 5%; T2 = 0.0207). While all studied interventions emphasized neuromuscular training, players who participated in programs including balance boards exhibited a significantly lower risk of sustaining ACL rupture (RR = 0.49; 95% CI, 0.35-0.67; P < 0.01; I2 = 74%; T2 = 0.5800).

Conclusion

Athletes who did not partake in an ACL injury prevention program were nearly twice as likely to sustain an ACL rupture compared to those who did, with particular ACL injury risk reduction in collegiate/professional athletes over age 18 and those who used balance boards. This study provides strong support for using neuromuscular training programs to significantly reduce the risk of ACL rupture among athletes.