This article is well written (maybe better than I could do), however there are a few flaws in this article.

Even if you agree that causality can't be found with small studies, the belief in causality is wrong in complex and unbounded situation, like talking about the human body. Causality is an ancient simplistic idea coming from the need for our brain to take quick response to events. If we want to evolve we need to drop that old belief.

Indeed, there is no mathematical causality operator. The only thing science can do is correlation. Therefore causality is at best an interpretation. Then, in experimental science where most parameters of the situation are unknown it is presumptuous to find the most probable cause.

My point of view is that when people run and or walk with thick soft soles and heel first since their childhood it is obvious that problems arise. As a MD you know how complex is the foot mechanic, also acting as blood pumps, and the implication on all the body and mind through the fascia network.

Like for causality, we need to drop all that small studies for switching to huge cohort studies.

I genuinely hope my remarks did not offend you, they can open the debate, and you can give me your thoughts about them.