Prescribed orthotics not helping. still bad pain in right foot only when running. do running shoes for flat feet need adjustment period as well?

Anything new: Typically needs some break in particularly. When it is different than what you were using before.

orthotics: Orthotics need a break-in period as they change angular relationships. See your prescribing podiatrist for help as your question does not state how long you have had them, how long you were/are in pain , etc. God luck.

Sometimes: Orthotics need adjustment so see your podiatrist for correct fit.