When anyone suffers an injury or is in pain, it is completely natural to wonder what went wrong and how we can avoid it from happening again. In most cases, it boils down to a simple equation of load versus capacity. Every tissue in the body has a certain capacity. If we apply a load that's much greater than the tissue's capacity, there is a higher risk of pain or injury. But if we apply that load slowly over time and actually give time for the tissues to make adaptations to that load, we should be fine because the capacity of those tissues will slowly increase. For example, muscles will get stronger, bone density will increase, tendons become more resilient. However, if we apply that load quicker than the tissues can adapt, we are more likely to get injured. For example, if you drop a brick on your foot, the load is much greater than the capacity, and it is applied abruptly so there is no time for adaptation.
While that example may be amusing, the more common scenario we see is someone who starts a new activity quickly. Again the load is greater than the capacity, and although it isn't as abrupt as trauma, it is still quicker than the body's ability to adapt, so the tissues start getting damaged and the capacity actually goes down. In both these situations, the load is applied faster than the tissue can adapt. On the other hand, sometimes we're smart and we keep a workout routine or running load constant. All is well until stress, illness, poor nutrition, not enough sleep, or many other factors reduce the capacity by hindering our ability to recover from each workout, and the capacity goes down. This lowered capacity also leaves us more vulnerable to injury. And in addition, pain can also be influenced by our beliefs, expectations, past experiences, and other things that are happening in our lives. So most injuries can be attributed to this load-capacity relationship.
Unfortunately, many people are told that their pain is due to biomechanical abnormalities, such as asymmetries in their anatomy or that they just move wrong. Examples of this can include a short leg, flat feet, their glutes not activating, their sacrum is out of place, or other things. These factors have been researched, and the conclusions are that many simply don't even exist. Of those that do exist, they may very well lead to higher stresses on certain tissues, but even then they play a small, if any, role in pain or injury. The fact remains if you give the body enough time to adapt, injury and pain are unlikely, even when we're not built perfectly or we don't move perfectly.
If you've ever watched the Paralympics, you quickly realize that humans are capable of performing at extremely high levels while possessing massive asymmetries and compensations, as long as you give the body time to adapt to the loads. We need to keep this in mind when thinking of the real cause of most injuries. Try not to get down on yourself in thinking that you're defective in some way, and don't be over analytical about how you move. Just think back about where you changed something too rapidly in your sport, your running, or your daily life. We also need to remember this if we somehow do get pain or injury. Once injured, it may become necessary to temporarily reduce the load with some rest.
But remember that if time of protection becomes prolonged, the tissue capacity will also reduce, and consequently less load is required to get injured again. This makes it necessary to make a slow return to previous levels of activity. The important thing to remember is that in the long run keeping some mechanical stress applied to the body is a good thing, as long as we respect the time it takes for the body to adapt. Be sedentary, and your body will adapt by reducing its capacity. Gradually and slowly increase in activity, and your body will adapt by increasing its capacity. Do it too quickly, and you may get injured. But if you remember the concepts of load versus capacity and tissue adaptation, you're on your way to understanding the root cause of most pain and injuries.