Someone whose ankle joint is very stable is better off wearing flat shoes, as long as they are supportive.

If your foot is at a right Angle to your outstretched leg and does not dangle, you have a low ankle-joint axis and will be more comfortable in flat shoes than in high heels.

Deformities include flat feet, hammer toes, overlapping toes, halux valgus, joint subluxation, prominent metatarsal heads, medial convexity (Charcot foot) and amputation.