Limited footwear, on the opposite foot, compress the foot, leading to improved strain over the metatarsals, which could bring about pain and inflammation characteristic of Metatarsalgia. Usually use proper athletic shoes when exercising. You should not use the knowledge contained herein for diagnosing a health and fitness or Exercise issue https://www.theorthopaedicandpainpractice.com/effective-treatments-for-ball-of-foot-pain/