If you are involved in a sport, it is likely that you’ve watched a friend tear their ACL (Anterior Cruciate Ligament), or torn one yourself. You’ve likely seen what a long and effortful process of rehabilitation can be. Understanding how to minimize your future risk for ACL tears can help you confidently participate in your sport.
In this article, I will share strategies to combat injury risk along with addressing common questions on this topic. Specifically, I will discuss:
- What is the ACL?
- How likely you are to get an ACL tear during a typical training season.
- The average cost and timeline associated with ACL repair.
- Injury prevention strategies and programs.
What is the ACL?
The ACL or Anterior Cruciate ligament is a band-like structure made primarily of collagen that is located inside of your knee joint. Ligaments perform several functions, but their primary role is to provide stability. However, they differ from muscle in that they cannot contract, and rely on passive tension to provide this stability. The ACL’s primary role is to provide stability in the knee and prevent the lower leg (tibia) from sliding forward on your femur when your knee bends or extends. It is assisted in this function by several muscles including the calf, the hamstring, and the quadriceps. Why it tears is a complex topic involving several variables. However, ACL tears most often occur during cutting and pivoting sports where the knee rotates as the lower-leg translates forward simultaneously, resulting in a tear to the ligament.
How likely are you to get an ACL tera during your season?
Data suggests that between 0.05 to 4% of athletes tear their ACL each year. This number may seem relatively small, but if 4% of your team tears their ACL each year, that would mean 16% of your team is out during some point in a typical 4-year stint of high school or college sport. That’s about 1 in 6 players!
Even more startling is the data showing that 20-40% of athletes will have an ACL tear on the same or opposite side after recovering from an ACL repair. This means that ⅕ to ½ of individuals will have a repeat ACL injury on the same or opposite side after undergoing an ACL repair. These numbers are startling!
Yikes! So what can we do?
Although these numbers look a little bleak, we know there are several factors we can address to reduce these numbers. One factor is simply being patient and not returning to sport too early. 75% of re-tears occur within 2-years of initial injury, and athletes are 7-times more likely to re-tear if they return to their sport before 9 months after an ACL repair.
However, this does not mean you should just sit around and wait if you have recently torn your ACL. Strength, mobility, and confidence all play a role in ACL injury risk so restoring these factors is critical. Below I discuss more detailed strategies for reducing your risk for ACL injury or re-injury.
The cost and recovery time following an ACL repair
Billions of dollars are spent each year on ACL repair surgery. Data from 2005-2013 illustrates that an average ACL repair surgery typically costs $10,000-$15,000, but may be much higher depending on various factors. Likewise, good quality rehabilitation typically lasts 9-12 months (at least) adding additional costs to the process.
If you have good insurance coverage, you may not be as concerned with the cost of surgery and physical therapy. However, many athletes are caught off guard when they hear that it will take at least 9-12 months to return to full sport participation. Not only is your risk of re-injury higher with earlier return-to-sport, but many factors such as range of motion, strength, power, and agility, need to be at or above pre-injury levels in order for you to be confident that your risk for re-injury is as low as is possible. Significant effort and time are required to achieve the appropriate milestones to minimize risk for future injury. Working with an experienced physical therapist that frequently sees this type of injury, and is equipped to measure strength, power, and agility will ensure you reach all the milestones you need to get back to your sport.
What do I do to minimize my risk for an ACL tear? The evidence.
There is not a perfect program that completely eliminates all risk for injury. However, injury risk can be reduced by 40-60% by participating in an injury prevention program.
Many different programs exist such as the 11+ but generally one prevention program has not been shown to be superior to another. More important, is understanding what goes into an ACL prevention program, and what you can do to minimize your own risk for ACL injury.
Injury prevention programs typically include 3 main factors:
One of the most important factors in ACL injury prevention is consistent performance of a strength and conditioning program at least two days per week.
This program should include:
- Compound lifts such as squats and deadlifts (at minimum)
- Progress to include single-leg variations
- Muscle group specific strength exercises
- Coaching by a Physical Therapist and/or Strength and Conditioning Specialist
More and more often, teams are involving strength and conditioning as part of their training during the season, but depending on the level and the sport, they may not. Working with a coach, physical therapist, or strength and conditioning specialist to develop a personalized program that considers your training season and goals is one of the best ways to reduce your risk for ACL injury. Especially if you do not have previous experience participating in this type of program yourself
Plyometrics are exercises which involve fast lengthening and shortening of muscles and tendons. Many plyometric exercises are different types or variations of jumping and hopping.
The goal is to increase your ability to produce force quickly with your muscles, often referred to as ‘Power’. ACL injuries often occur in less than 200 milliseconds so having the ability to produce force quickly may just spare you from that ACL injury.
Plyometric exercises are most effective when not performed on the same day as a strength training day. If you are short on time, they may be done on the same day, but they should be performed at the beginning of the workout when you are less fatigued. Again, working with a physical therapist, coach, or strength and conditioning specialist is a great way to ensure you are including each of these factors in a program that works for you and considers your goals.
Focus on Proximal Control and Balance
Balance, coordination, and control are somewhat complex systems that help us to understand where our body is moving in space, and perform efficient movement. The ACL is full of receptors that help our brain to understand what the knee is doing, and how to adjust movements efficiently. When the ACL tears, we lose these receptors, and the graft is not able to regain this function because nerve fibers do not innervate the new graft. Instead, our bodies rely on using other sensory information from our knee, our eyes, and our muscles to maintain control.
Whether you have injured your ACL or not, incorporating some challenging balance tasks such as single-leg standing on the ground, or on unstable surfaces, is just one way to ensure you have sufficient balance control to reduce injury risk. Other tasks such single-leg landings and perturbations while balancing can make the balance challenge more significant. Performing these balance tasks in addition to strength and plyometric training will round-out your injury prevention program.
Using an ACL injury prevention program to reduce your risk for an ACL tear can save you time, effort and money in the long-term. Although risk cannot be completely eliminated, risk for ACL injury can be reduced by as much as 40-60%. These programs are fairly easy to incorporate on an individual level, or a team level, and should be performed at least 2 days per week. Strength, plyometrics, focus on proximal control, and balance training are the most important components of any successful ACL program. If you are unsure how to get started, talking with a physical therapist and strength and conditioning specialist will allow you to set up a program that will minimize your risk for future injury.