These posterior tibial tendon maintenance exercises are intended for stages 1 and 2. When you are not exercising, it's important that you consistently use arch and ankle support to prevent the inner ankle from rotating inward and down (supination or eversion), and the foot arch from sinking down (a condition called Adult acquired flat foot). Orthotics to support the inner edge of the heel, together with archsupport running shoes, are advised. If that does not reduce the pain, do not worry about being fashionable and start wearing hiking boots to support the ankle. And please seek a professional opinion. Because this problem takes time and multiple strategies. You can fix it. But you've got to be diligent!

For more information and other pilates solutions, go to:
https://www.btpilates.co.nz/
https://brucethomson.substack.com/