Back in 2018, I wrote briefly about my experiences with running and back pain. Skip forward to August 2019, I got a custom-made pair of insoles, focussing on arch support. It took a couple of weeks to get used to them, but I've gone from having to be very careful regarding back pain and day-to-day life to a fully-functioning life.
This is so thorough that if I don't wear the insoles for a few days (being barefoot around the house, for example), my back can become problematic. Walking around with them in greatly helps resolve the issue.
TL;DR? If you have back pain, see if bespoke insoles can improve things.