When you first begin wearing them, you may need to wear them more often to help your body adjust. However, you shouldn't wear foot orthotics like cast shoes, for example, all of the time. The muscles in your feet will become reliant on them and you will have trouble walking without them. They should be used for a set period of time. If they need to be worn for years, then you should consider taking breaks and working on strengthening exercises for your feet and legs, if possible.