Not sure what you're using now. My foot and knee pain went away when I stopped using clipless and started using flats (FiveTen Freerider shoes, Dmr Vault pedals).
https://www.adidasoutdoor.com/five-t...shoe/FT07.html
https://www.dmrbikes.com/Catalogue/P...lt-2/Vault-NEW
Things that caused me issues:
- Clipless pedals (yeah not a problem for everyone but they were for me)
- Cheap plastic square flat pedals - slick surface let my foot slip around and my leg would try to stop it from slipping and it would cause issues
- Smaller pedals - I have big feet and if the pedal platform wasn't big enough my feet would hurt
- Pedals with no concave - no huge issues just not as comfortable, my feet like the pedals with a concave shape better
Five Ten shoes use a special sticky rubber that grabs to metal pins like they're clipless (except you can lift your foot off the pedal easily). Dmr Vaults have the pins, are big enough for my feet, slight concave shape is very comfortable.
Obviously a certain level of medical problems will mean one cannot bike period at some point so I don't know if this would help. But this is the most comfortable I've found for my knees and legs.