Why Distance Running Doesn't Cause Arthritis

Marathon runners are less likely to have knee arthritis than the general population. That was the conclusion of a 2018 study in the Journal of Bone and Joint Surgery. Of the 675 distance runners studied, each with a minimum of 5 marathons completed, and a mean age of 48, arthritis was reported by 8.8% of the participants. The general U.S. population has an incidence of 17.8% when adjusted by age, sex, body mass index, and physical activity level, as to compare the two groups. This particular study had limitations and should not be considered conclusive, but research continues to mount showing that there is no correlation or even a negative correlation between distance running and arthritis. How can this be? How can so much physical activity and pounding of the joints not lead to joint breakdown?

Some might say that people with stronger joints gravitate to running and therefore it is a self-selective activity only taken up by those that will not experience joint damage. In some cases, genetics and bony morphology come into play, but I believe this is only a small number of people. By and large, individuals who are successful at distance running do not experience arthritic changes faster than the average population simply because, have good running form. They know how to use their bodies in a way that doesn’t promote breakdown. Our bodies are tremendously resilient when forces are applied to the right tissues in the right way. This means they are able to transmit forces through their joints while keeping them in a mid-range position. Mid-range meaning that the joint surfaces stay stable, with good congruity, so they still have room to move in any direction. Therefore, it is not about how much someone runs, but how they run, that will determine how much wear and tear their joints will suffer. This idea is true for all physical activities.

Perhaps you are thinking, well that is interesting and all, but it has been quite some time since I’ve run, so what does this have to do with me? I’m frequently asked by my patients if it is okay to walk, take stairs, dance, play tennis, garden, etc. The answer is always the same. It is not about what you do, but about how you do it. Any of these activities can be completely benign or terribly painful depending on if you can maintain joint stability as you do them.

So let’s talk about stability. We need to create stability in our joints in order to transfer force from our muscles to our bones and then to the world around us. It is a requirement, not a choice. We have two options to create joint stability. We can either hold a joint stable through muscle engagement or we can find stability through the tension of our supporting structures like ligaments or tendons. Think about the difference between sitting upright or slouching. Upright requires muscle activation and control. From that position, you can move easily in any direction. While slouching you aren’t using much muscle activity and you are being held up by the tension of the ligaments along your spine. The upright position is less strenuous on your tissues but takes energy and can be tiring. Slouching allows you to rest but places more strain on your body and holds your joints in a less aligned position. Both strategies have a role in healthy movement, but for prolonged or higher intensity physical activity we are much better served by muscular stability.

Every person, regardless of athleticism, size, or the amount of cartilage between their bones will feel stronger and less painful if they are able to use their muscles to find stability and alignment in their joints during activity. We accomplish this through adequate strength, flexibility, balance, structural integrity, and coordination. I will delve deeper into these 5 pillars of stability in next week’s post so keep an eye out for that if you find this as interesting as I do.

As always, if you have any questions feel free to reach out to me at [email protected]