Exercise-Based Knee and Anterior Cruciate Ligament Injury Prevention – Clinical Practice Guidelines
JOSPT, September 2018
Arundale Et. Al
Fresh off the press, new clinical practice guideline recommendations are out for knee and ACL injury prevention programs. ACL injury, surgery, and rehabilitation can be a long, painful, and expensive event, so why not look towards prevention? The paper’s a great summary of what programs seem to work, who are effective targets for the intervention, and appropriate implementation.
What Programs Are Effective?
The CPG presented various exercise-based prevention programs that demonstrated effectiveness in decreasing injury risk for both general knee-related and ACL-specific injury. Some hyperlinks are below, but you can find even more access and links on page 20 in the article.
Effective Programs for General Knee Injury Prevention:
- FIFA 11 and 11+
- HarmoKnee
- Knakontrol – App available!
- Various authors programs: Emergy and Meeuwisse, Goodall, Junge, LaBella, Malliou, Olsen, Pasanen, Peterson, and Wedderkopp. See the CPG for more direct links to these.
Effective Programs for ACL-Specific Injury Prevention:
- HarmoKnee
- Knackontrol
- Prevent Injury and Enhance Performance (PEP)
- Sports-Metrics
- Various authors programs: Caraffa, Heidit, Labella, Myklebust, Olsen, and Peterson. See the CPG for more direct links to these
How Effective Are These Programs?
The pooled incidence rate ratio based on 19,143 subjects (19 studies) showed that exercise prevention programs have the ability to reduce the incidence rate ratio of general knee injuries to 0.73. One study included in the CPG found a pooled rate ratio for ACL injury prevention programs (N of 27,000) to be 0.46. The relative risk reduction for exercise prevention programs ranged from a decrease of 43.8% to 70%. With regards of numbers needed to treat / benefit, the evidence points towards an NNT between 89 to 120.
Demographic-wise, females of ages 14-18 have great evidence for this sub-group receiving the most benefit from prevention programs. When adherent to an effective program, females under age 18 have their odds ratio for knee injury improved to as low as 0.27 whereas females over the age of 18 only receive a benefit of a 0.78 odds ratio. Unfortunately, based on the current evidence, females over the age of 20 don’t seem to receive an improved odds ratio for reducing knee injury with prevention programs.
What Should a Good Exercise-Based Prevention Program Include?
Unfortunately, you can’t “just strengthen” or “just stretch” and expect a good program. All of the effective programs were multi-factorial and included a combination of proximal control exercises, strength, and plyometrics. Programs with more than 1 component had a 0.32 odds ratio, whereas those with only one component had a 1.15 odds ratio (not good). Interestingly enough, programs may not need to have a balance component as programs had a 0.34 odds ratio with or without the balance component.
Athletes should be performing these programs multiple times per week, with sessions at least 20 minutes in length and with a total volume of over 30 minutes per week. Doing over 30 minutes weekly improves the odds ratio by over twice (0.32 vs. 0.66) compared to less than 15 minutes a week.
The CPG suggests programs should start during the preseason and continue on throughout the regular season as programs greater than 14 months had a 0.41 incident rate ratio.
Compliance Matters!
All these numbers, suggestions, and evidence are fairly impressive and seem obvious to execute. Unfortunately, they may not be beneficial unless the athlete has a minimum level of compliance. The numbers show that you need at least 64% or greater compliance in order to achieve the 0.39 incidence rate ratio (optimal prevention range). This can be quite a challenge when you think about needing athletes to do a 20-minute session and multiple times per week. To make this happen you’ll certainly need a coach, team, and club to buy-in as a whole. The programs do not necessarily have to be led solely by medical professionals and can be led just by coaches as well. With that said, I’d imagine it’d be advantageous for the coaches to be trained by medical professionals in order to ensure they are executed properly.
How Much Could This Save $$?
A cost-benefit analysis with athletes aged 12-25 years old playing high-risk sports revealed a future health care costs avoided amount of $693 a person. Adhering to prevention programs can also decrease the costs associated with possible future sequala, such as osteoarthritis and total knee arthroplasty.
Call To Action
If you’re in the area of sports, ACL injury rehabilitation, or working with teams then definitely give this clinical practice guideline a read. A wealth of A-grade recommendations are summarized and are expounded upon with referenced articles in the paper. Furthermore, the authors put out 2 videos in the supplemental material that I’ll link to below. This CPG is a great start towards standardizing the components of exercise-based prevention programs, but we certainly need more evidence on the topic, such RCTs and not just meta-analysis and systematic reviews, especially for populations that haven’t been deeply explored.
Tyler Cope
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