Toes may curl for a variety of reasons, some of which are the result of health conditions and others which are not. Diabetes and arthritis can be contributing factors, while certain foot shapes can also predispose individuals to the development of joint deformities. However, some patients visit Advanced Foot & Ankle Specialists with no such preexisting conditions. In many of these instances, ill-fitting shoes are the culprit behind toe curls. High heels or shoes that fit improperly can cause toes to become crowded and force them into a bent position. Over time, this pressure on toes and joints causes muscles to shorten or tighten, which minimizes mobility and causes them to curl.