A systems approach to hamstring injuries
There is a strange phenomenon when it comes to hamstring injuries. With most other injuries, we tend to point the finger at movement. What caused an ACL tear or shoulder pain? Bad mechanics or the athlete put themselves in a bad position. But what caused the hamstring injury? Weakness most often gets the blame. Why do we think about hamstring injuries differently? Could a change in mindset help us reverse the concerning hamstring injury trends in many sports?
Systems vs reductionist thinking
For some reason we tend to take a different mindset when it comes to muscle injuries vs. joint injuries. Muscle injuries are often treated with a reductionist approach. Reductionist thinking tries to simplify the process by focusing on specific details. In this view a system is a sum of its parts, therefore fix the parts and you’ll fix the system. What part do we focus on most with muscle injuries? We focus on the part we can measure the easiest: strength. We shouldn’t forget that we need to measure what is important, rather than making something important simply because we can measure it.
A systems approach, on the other hand, takes a holistic perspective. A system is the result of how parts interact. Fixing the system is about understand and optimizing those interactions.
When it comes to the ever-growing challenge of hamstring issues a reductionist approach has taken centre stage: hamstrings are getting injured since they are too weak. The solution: make the hamstring stronger and it will no longer break. Rather than fixing the problem this has just created a paradox: we focus more and more on hamstring strength, but the problem keeps getting worse.
Systems approach to the hamstring
Reductionist thinking can work with simple problems. But complex problems and movements demand a more holistic viewpoint. If strength were the answer, then why do strong people always get hurt? More and more research has started to debunk the simple promises of the reductionist approach.
In the niche world of hammer throwing hamstring issues are not prominent, but another reductionist approach is front and center. Many hammer throwers are plagued by low back pain which the reductionist approach blames on poor core strength and stability. While many coaches still hold this view, over the years the myth of core stability has been revealed. Hammer throwers have incredibly core strength, but that doesn’t solve the problem. Why? They are often putting their bodies in awkward positions while requiring it to counter a few hundred kilos of force. Fix the movement and the pain often disappears. It’s time for a similar revolution in thought when it comes to hamstring injuries.
A systems approach would look at the hamstring in the context of the running movement. Sure, the hamstring might be too weak, but perhaps the issue is that we’re putting the hamstring in a position where it’s being required to work at sub optimal lengths. No wonder it breaks.
It’s not that we need to ignore strength. Strength is still one component, but the hamstring debate now seems to be about whether eccentric or isometric hamstring exercises are the best. Or, whether regular exposure to maximum speed sprinting is the cure. All these solutions still use a reductionist approach by focusing on a single factor. That factor might play a role, but it isn’t the solution to every problem. If running mechanics are poor, simply adding more strength or exposure to high intensity running isn’t going to solve that.
The car analogy
To help look at where the reductionist thinking falls short, let’s take it outside of a sporting context. If a car keeps getting into accidents or breaking down, what is the cause? We can’t say without knowing more, right? It could be any number of things: mechanical issues, poor tire pressure, balancing if the wheels, word down brake pads, poor handling, lack of power, etc. A reductionist approach often picks one of those reasons and focuses on it in order to prevent future accidents without ever reading the accident report.
More often than not, accidents are caused by a complex combination of factors. The driver might be distracted. Once they realize they are in a bad situation the car’s handling is a bit slow to turn away. Then they punch the gas to further evade the issue but there just isn’t enough juice to escape the situation. How do we prevent future accidents in this chaotic environment? It’s complex, but the central element of it all is the driver. The driver controls the system. Want to avoid most accidents? Become a better driver. That means increasing awareness of the surroundings, being defensive to potential threats, knowing how your car responds, and what options you have to work with. You make the system stronger, and you’ll avoid most accidents.
A case study in sprinting
Let’s now look at a systems approach in the context of a common issue with hamstring injuries in field sport athletes. It is becoming widely accepted that there are a few main contributors to soft tissue injury associated with sprinting: pelvic control across multiple planes of movement and collapse of the ankle. However, the most significant issue, especially in field sports, is excessive anterior pelvic tilt. There are a number factors why this occurs at speed. The most common being allowing the leg to spend a disproportionate amount of time behind the body – commonly known as excessive “backside mechanics.” As such, the pelvis has no option, but to rotate forward. This rotation also puts an increased pre-stretch on the hamstring and can contribute to hamstring issues. You can see this in the famous example from Peter Weyand‘s lab comparing the mechanics of a sprinter and a field sport athlete:
A systems approach, on the other hand, also looks beyond strength at improving sprint posture and motor learning. A systems approach asks: why did the athlete have poor lumbo-pelvic control in the first place? Perhaps poor foot strike and in turn, collapse at the ankle resulted in a longer ground contact time. Longer ground contact time caused the foot to trail behind the body. This then has a knock-on effect of the pelvis tilting anteriorly as the next stride begins. Clean up the foot strike and maybe the athlete is never in the compromising position in the first place. Problem solved. Correct force application = good posture. Good posture = correct force application.
Using a system approach reframes the issue, but it does not solve the problem. In the case study above we might have come to a better answer as to what caused the injury, but we are only part of the way to fixing it. The next question is how to address this in our programming and coaching. Social media is flooded with running drills and apparent solutions for these flaws. Less convincing though, is witnessing the practical applications of these solutions. More often than not it is just pseudo training activity; lots of movement without any direction. A systems approach also needs a systems solution where the training precision, intensity, and complexity are all prescribed specifically to the task at hand using sound teaching concepts.
The solution isn’t always this easy, but the example shows how a change in mindset from reductionist to systems–from muscles to movements–can help reframe the problem and open up new possible solutions. Unfortunately, we aren’t hearing this side of the discussion in the hamstring debates, but it’s time for that to change.