Are ACL injuries epidemic?
Does it have to do with improved communication or faster dissemination of news, but it seems that there were never more cruciate ligament injuries than at present. Last weekend a professional soccer player in Belgium, a few days later one in the Netherlands, England, Spain, and when you read the newspaper … just watch the lower divisions as well. Not a week passes without a soccer player is getting injured at the anterior cruciate ligament (ACL).
What’s going on?
Some blame the many cruciate ligaments injuries to the faster game, others to the artificial grass, others to the shoes, or …?
The faster game could be a cause but would that not only be at the highest level? Artificial grass is still rather exceptional in our region and why weren’t there a lot of ACL injuries previously when people still played in ‘the meadow’? And how much research is focusing on improving shoe performance?
Or are we missing something else?
What are the causes of ACL injuries?
To reduce the number of ACL injuries it’s important to know the cause of this injury, so we can determine a strategy to counter them. Some cruciate ligaments injuries are caused by contacts, which we can’t anticipate since soccer is a contact sports (same applies for other contact sports). But we also see a large number of non-contact injuries at players, without an opponent nearby, who rather unexpectedly injure their anterior cruciate ligament. It’s often an exaggerated rotation component between upper leg (femur) and lower leg (tibia) which causes extreme stress in the ligament making it fail eventually. Think of a foot which gets stuck in the turf.
Keep in mind that the rotation can arise from three perspectives: the upper leg rotates outward relative to the lower leg; the lower leg rotates inward relative to the upper leg; upper and lower leg rotate simultaneously away from each other. The injury seems to be not as dramatic as a broken leg; however on the other hand rehabilitation will take at least six months to one year. A lot of athletes even suffer consecutive ACL injuries (relapse).
Preventing ACL injuries?
We have listened to a number of organizations and health professionals who claim to prevent injuries and we now have an idea how they cope with ACL injuries. Also the (professional) soccer teams are doing their best to avoid this type of injury using appropriate exercises. Therefore our attention went to their thinking, strategy and exercises. The most common solution was ‘stability training’ of the trunk, knee and ankle. Rehabilitation specialists indicate an excess rotation in the knee as the cause of cruciate ligament injury and they want to teach the knee to go straight forward instead of moving inward (in other words rotating internally) by applying specific ‘stability exercises’. This knee stability is considered to be THE prevention technique of ACL injuries.
Examples of exercises
Most exercises, also in rehabilitation, focus on letting the knee go straight forward and on avoiding internal rotation, possibly with tubes around the knee for muscle strengthening. Another example was the trunk stability, performing benches … because when the trunk and hip are stable…
Injury prevention? When do you end up in this position while playing soccer? How will this help you?
We now also have examined a number of companies who are providing exercise programs online with a wide range of exercises in which, according to them, the knee must move straight forward and if not … there are more exercises to steer the knee. When we asked further explanation about ‘why’ they believe the knee has to move forward, they usually referred to another employee who had developed the program…
And then we looked at all this with a critical eye 😉
The first question we asked ourselves: Why is it that, even when performing stability training and corrective exercises more frequently compared to before, we still see so many ACL injuries? Or would there be more injuries in case we won’t perform ‘stability training’?
Another question might be: Why is the knee not allowed to fall inward, when due to the eversion (falling inward) of the heel bone (calcaneus) when hitting the ground, there will be a pronation movement in the foot (going through the medial arch) which causes internal rotation of the knee?
Let me explain: With every step you take, the falling inward of the heel bone (eversion) will cause a pronation movement in the foot, i.e. your medial arch (the bridge on the inside of your foot) is reduced and because of that pronation there will be a rotational movement of the tibia, including the knee.
And how are we going to prevent the knee of falling inward using stability training if this is a movement which according to the biomechanics of the body MUST be there? And which muscles are crucial to counter the internal rotation of the knee?
So why would we perform exercises in which the knee moves forward if the knee falls inward or turns in many activities? Just try to perform a ‘lunge’ and rotate with both arms at shoulder height away from the front leg, so for example, right leg in front, shoulder and trunk rotation to the left. Where is your knee going? And now turn with both arms at shoulder height to the front leg. Where is your knee going?
When we know how the biomechanics of our body works, how wise is it to train the knee for something it rarely has to do (moving forward)?
What is the reason that, even after a successful surgery, athletes or recreational players still relapse into the same injury? Are we missing something in our rehabilitation?
And how will stability training, as we see it performed by so many clubs, trainers and physiotherapists (static bench, knee, hip, ankle), help our body in an activity like soccer, in which we perform a lot of different movements and move in numerous directions?
Stability training does not mean keeping quiet, but stabilizing from movement (from stretch). This principle is often misunderstood and frequently used by people who lack training and understanding. The intentions are good, but the techniques could be improved, at least if you believe that ‘mostability’ (motion + stability) would be a better implementation. To cut a long story short you can summarize it like this : You are what you train: To become faster you train speed, to jump higher you train jumping power… if you train like a bench … you become a bench…
You won’t probably like reading this if you’re a trainer or physiotherapist for years and you request your players / customers to perform ‘stability training’ in this way… Don’t worry, we did it too… previously! Only we started to think differently about some things and we wanted to bring more logic into our coaching. The switch from static to dynamic, from lying on the ground to stance does not require that much adjustment…
It’s extremely confusing when a large organ such as FIFA distributes posters and exercise programs explaining for example to maintain the bench for 20 or 30 seconds.
The basis of injury prevention
It’s important to know how the body works, how the biomechanics of the human body works and how all our systems, such as muscles, fascia and nervous system function. Once we know what movements to expect in certain activities, such as soccer, a way to prevent injuries is to detect or avoid compensations. For example, when the knee falls inward, the large gluteal muscle is activated to return the knee from its internal rotation. A poor timing or insufficient activation of the gluteal muscle can cause injuries such as the ones at the cruciate ligaments. Performing benches like shown in the movie regarding stability training or exercises that don’t resemble realistic movements (like most machines in the gym) will confuse our nervous system (proprioceptors) and disrupt the timing. Preferably we train our body in the most logical way, in a way it functions and works. Training the knee to ‘move forward’ seems not a good idea because it isn’t something (or not only something) that our knee does when playing soccer. Feel free to look for slow-motion footage of a soccer game and watch in which directions the knee moves.
If a compensation of the body is the cause of the injury, there is a high probability of relapse for as long the cause has not been detected. A surgery restores the damage (and we have great surgeons to do that) however motion analysis and thoroughly building in a logical manner is essential for a healthy knee.
We could easily distinguish the cause of ACL injuries between recreational and elite athletes. The impact of e.g. a sedentary job is amazing: short hip flexors, decrease of the activation of the buttocks, fixed ankles (subtalar). For elite athletes we have our doubts about ‘stability training’, steering the knee, the machines in the gym, performing unnatural movements, abdominal training on the ground, etc …
Avoid movements Training movements
A final fact to think about: What’s according to you the best way to protect your cruciate ligaments?
What if we are wrong and we maintain the techniques as currently implemented …. and the knee shouldn’t fall inward? Then we opt for the following strategy: You train your body so that your knee can no longer fall inward!
OR: We are right and we train your body (and not just the knee because that’s only part of the chain) so that it’s perfectly capable of withstanding all movements (such as falling inward of the knee)?
Which one would you choose?