1. People who have any of the following conditions:
• very tight calf muscles
• severe arthritis with fused joints
• ankle or subtalar joint fusion
• diabetes, especially with neuropathy
• fibromyalgia
• a history of significant back injury, especially with surgery
2. People who only wear sandals and high heels.
3. People who cannot wear them consistently. In some people, it does more harm to wear them inconsistently.