Let's look at the orthotic prescription variables for blisters under the first metatarsal head. Your choice will depend on the stiffness of the ray.
Orthotics can cause posterior heel edge blisters when they sit ever so slightly forward in the shoe. Thankfully, there's an easy fix.
A weightbearing blister can be devastatingly painful when you have to keep walking and running on it. Find out what you'll need to give it real relief.