The Formula for Injury & Pain
There is quite a simple formula for why pain occurs and why an injury develops. The formula is simple, but the science and the variation from individual certainly is not. Thankfully, this is why osteopathy exists. Using the holistic thought process of osteopathy, your osteopath will provide a comprehensive examination after they have heard your detailed story. Everyone has a unique story on why they might be experiencing pain and why the injury developed. If you have already seen myself for an opinion or been following my previous blogs. You will constantly hear or see me talk about “load” and “capacity”. If you have ever been a little confused on what I am talking about, this blog is certainly for you. I will reveal what the simple pain and injury formula is, and the intricacies of this formula.
What is the formula for pain & injury?
The simple equation is load vs capacity. Every tissue in the body has a certain capacity. If we apply a load that is far greater than the capacity, the overall injury risk is high. This is when we enter the danger zone, and you will often experience pain or discomfort at this stage. This is when seeking the guidance of an evidence-based osteopath who understands sport and exercise is recommended. At this stage we would provide education and injury risk mitigation rehabilitation so that your pain does not evolve into an injury. When the load is applied slowly over time and the tissue capacity is not heavily exceeded, positive adaptation is possible. Positive adaptation usually occurs when you listen to the body and prioritise recovery after training. This positive adaptation is how our muscles get stronger, our bones become denser, and our tendons become more elastic and resilient.
The load cannot exceed the tissues capacity to recover and adapt! Once injury occurs due to the capacity being exceeded, capacity typically reduces, and our load threshold drops significantly. This is a major reason why rest after injury is not advised in most situations. The pain and injury will eventually heal with natural healing timeframes, however the tissue capacity has actually decreased. As we are not in pain or much discomfort anymore, we usually jump straight back in to training and significantly exceed the reduced capacity. This is how most injuries recur and why seeking a professional opinion early is highly recommended. I am evidence informed in the way I practice, so there are always rehabilitation options I provide that aid recovery and reduce tissue capacity deficits. For example, if you suffer a muscle strain we will certainly be loading it back up day one of the injury!
What is Load?
A very common misconception and belief is that load simply is how much you lift, run, throw, etc. This is simply one part of the load equation and it is arguably not even the most important factor. Load is divided into external load and internal load.
External Load
External load is the total amount of work produced or performed by the individual/ athlete. This is what most people only see load as. Examples of external load are the distance ran, steps taken, balls thrown, total weight lifted, total distance sprinted, laps swam or kilometres cycled. With the advancements in technology, we can track our external load by apps or smart watches. I am an advocate of the Garmin watch for athletic activities.
Internal Load
Internal load is the psychological and physiological stresses that are imposed on the individual/athlete. Internal load is arguably more important than external load when it comes down to our injury formula. This is a major reason why in my appointments I ask about sleep and stress levels, as these two factors have been heavily researched to influence injury/pain occurrence. Examples of internal load are sleep (most important), stress (high importance), nutrition, genetics, general health, medical history (diabetes), smoking, fear of movement, catastrophising thoughts, self-efficacy, beliefs about pain/injury, and overall psychological and social/support network. This is why I’m passionate about spreading helpful evidence-based advice and eliminating barriers to movement and function. Nocebic language like “lifting with a flexed spine will damage or injure your back” creates fear of movement and catastrophises a normal healthy movement our bodies are capable of. It all comes down to the capacity to tolerate the loads that you are lifting with that flexed spine. If you have built up the capacity to tolerate that load, injury risk is low.
An example on why internal load may be more important than external load is when two individuals run the same 5km track at the same pace. Their response to the external load (5km) may differ based off their internal load. Internal load factors are capable of reducing the load capacity and therefore, reduce the load tolerance to the stimulus. Runner 1 has been sleeping well, getting 8 hours minimum a night and describes their quality of life as 8/10. Whilst runner 2 sleeps poorly, struggling to get 5 hours a night and is highly stressed, with a quality of life ranking being 4/10. Runner 2, would have a significantly decreased capacity and therefore may respond poorly to the run, which may lead to them suffering an injury. Internal load can simply be summarised as the response to the external load.
Psychosocial measurements include our mood, self-efficacy, sleep patterns, stress levels/responses, social support and our fears/beliefs. Whilst physiological measurements include our hormone status, resting heart rate, blood pressure and heart rate variability.
Other definitions of load
Allostatic Load
Allostatic load or allostasis is an active response of the body to daily events to maintain homeostasis. A explained above, the body is always facing load from psychosocial, physiological and physical factors. The summation of these factors determines our overall load. When the body responds and the body returns to equilibrium in a timely fashion, allostasis occurs. This is when adaptation is possible and occurs so that we become more resilient and robust.
Absolute overload
The external load is simply too high (lifting double the weight you normally would). This can be summarised as too much too soon.
Relative overload
The external load is within what the individual normally completes, however the ability to tolerate this external load is reduced from a high internal load.
What is Capacity?
Our capacity can be defined as the ability to complete an activity at the volume and intensity required without causing tissue injury or an exacerbation in symptoms. Our capacity can be considered our injury threshold, the higher our capacity is, the less likely we are to suffer an injury. Our capacity is at the mercy of internal load factors! For the same individual/athlete, their response to the same external load can be vastly different on two different days based off the internal load.
Exercise rehabilitation is about improving our overall load capacity, by increasing our overall injury threshold. This is why strength and conditioning coaches who know what they are doing are worth their weight in gold. Having a good and long pre-season is known to be crucial for reducing injury risk as a result of improving the overall load capacity. This is information that I wish I was aware of when I was in my teens. I recommend that all parents consider exposing their children to structured strength and conditioning. It may be the difference between them spending more time on the sidelines and struggling to get back to their best or being the star of their chosen sport.
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