Orthotics are not risk-free. The risk is not large, and so not much needs to be said about it. However, good or bad, they can be difficult for a body to adjust to, disrupting fine-tuned postural adaptations and forcing awkward new ones.
I had a pair of hiking boots that I really wanted to love: beautiful, expensive boots that seemed to fit perfectly, and so sturdy. It was liking wearing cozy tanks! But they also consistently made my right foot ache about 20 minutes into every hike in a way that no other boot or shoe ever had before, or ever has since.
I kept those boots for years, trying them hopefully each hiking season. The pain was as as reliable as sunrise. Who can say what it was about those boots? What subtle interaction with my body? Nearly impossible to diagnose, I imagine. It was trivial but inevitable.
I’ve seen numerous examples over the years where orthotics seemed to have this kind of effect — just a temporary wrench in the works. In the worst cases, people simply ditched the orthotics and the problem was solved.
I think every pair of orthotics is a minor gamble with some potential to help … or do what those boots did.