In the review conducted by researchers at the University of Massachusetts (1), the authors pooled the data of 10 high quality studies that investigated the effectiveness of ACL injury prevention programs for female athletes. Soccer was the most common sport evaluated, with basketball, volleyball and handball also in the mix. Whilst the exercise regime varied in each of studies, there were similarities amongst the studies with plyometrics (jump & land exercises) being done in 80% of the studies, strength training 60%, and flexibility 40%. Plyometrics were included in 9/10 studies, and plyometrics demonstrated a positive trend toward reducing ACL injuries.
Most studies showed a decrease in ACL injuries with the intervention (only 2 with statistical significance), however there were two studies in the review that actually showed an increase in knee injuries by the groups that performed the injury prevention regime. The first of these studies used a combination of plyometric and agility exercises (2), and the second used (3) used balance exercises only.
The timing of when the programs were performed also revealed some interesting findings. Programs that were performed in the preseason resulted in a lower injury rate, whereas program done during in-season only resulted in a higher rate of injury. Programs also varied considerably in duration with effective programs being between 10 minutes and 60-90 minutes. Frequency was between 1-3 times per week.
As with many systematic reviews in sports and orthopaedic medicine, this review finds mixed results and only moderate evidence for the intervention, in this case for neuromuscular training programs to reduce ACL injuries. So how will this review change my practice? Firstly, I’ll continue to implement an individualised and ongoing injury prevention program for my ACL reconstruction patients including plyometic, balance, strength, and flexibility exercises. However I will place greater emphasis on performing these exercises in the pre-season, and reduce or eliminate the program during in season. I’ll keep it to a 15-20 minute program that is performed twice per week, and I’ll keep my eye on the literature for further research.
The two most well-known and used ACL neuromuscular programs are:
- The PEP Program: http://smsmf.org/smsf-programs/pep-program
- The FIFA 11+: http://f-marc.com/11plus/home/
- Stevenson JH, Beattie CS, Schwartz JB, Busconi DB. Assessing the Effectiveness of Neuromuscular Training Programs in Reducing the Incidence of Anterior Cruciate Ligament Injuries in Female Athletes: A Systematic Review. Am J Sports Med 2015 43: 482-490
- Pfeiffer RP, Shea KG, Roberts D, Grandstrand S, Bond L. Lack of effect of a knee ligament injury prevention program on the incidence of non-contact anterior cruciate ligament injury. J Bone Joint Surg Am. 2006;88(8):1769-1774.
- Soderman K, Werner S, Pietila T, Engstrom B, Alfredson H. Balance board training: prevention of traumatic injuries of the lower extremities in female soccer players? A prospective randomized intervention study. Knee Surg Sports Traumatol Arthrosc. 2000;8:356-363.