Over the last few decades there has been an increasing tendency towards doctors prescribing custom foot orthotics. In fact, a big part of my first job in chiropractic (as a chiropractic assistant) was to do custom foot impressions for a very successful chiropractor who also prescribed orthotics.
Back then, the thought was that the feet influenced the spine and when an custom orthotic was prescribed it would help fix the spinal problem. That was 20 years ago.
Now I am seeing more and more, clients I work with getting out of their orthotics as I properly correct their spine. My understanding is changing.