Repetitive sports-related injuries and progression of spondyloarthritis

Is there a risk that repetitive sports-related injuries accelerate the progression of spondyloarthritis?

Filip Van den Bosch: It is a very interesting question, because it challenges our concept that we should normally give treatment with exercise and physical therapy to patients with ankylosing spondylitis.

The evidence that this is good comes from historical studies, where patients were treated with physiotherapy and had a very good response or felt better. The evidence we have right now in humans with regard to physical exercise or physical stress and progression of the diseases is scarce. We have a few cohorts that suggest that if you have ankylosing spondylitis and perform physically hard work, your disease seems to be progressing more rapidly. That could be an argument to say, “Is there something there?” But that is the only thing we have in humans. For the time being, I would say that in humans we have not enough data to say “you should not do this” or “you should do that.” I think it is still very crucial that people keep moving, that they exercise. They should probably – this is common sense – stay away from very high-impact sports.

The only animal evidence that we have, which is quite challenging, is from an animal model that we explored in our department in Ghent. What we looked at was, we had a mouse model that developed spondyloarthritis, and then we did a very crucial thing in that the controlled mice were allowed to walk around their cages and then they developed spondyloarthritis in all their paws. The treated mice were suspended by their tails, so their hind legs were not touching the ground. Surprisingly, we did not find arthritis in the hind legs. The moment you unload [the mice] and they put physical stress back on the paws, they develop arthritis. So, in a mouse model at least, it looks like physical stress provokes something, but we do not know what to do with it and for the time being it is too early to say it is not a good idea. We should probably keep on exercising, but with common sense.

I think we should still advise our patients to keep on moving, because the major characteristic of inflammatory back pain or inflammatory joint pain is that it worsens if you rest. If you are not moving, you get morning stiffness, after a full night of sleep; or you get more stiffness. We should do something to keep our patients moving, but we should probably have a good, informed discussion with our patient to say, “Well, there are sports, activities, that seem to be less impactful than others…” – and then you automatically think about walking and swimming as potential exercises of a good nature – “…and then probably more impactful exercise,” like boxing, which would be something I would discourage my patients from.