Accessory Navicular

Although the foot has a standard 26 bones, there are some extra bones (accessory bones) that can occur in a percentage of people. The navicular bone is found in the middle of the foot on the inside just in front of the ankle. One of the major tendons of the foot (tibialis posterior tendon) attaches to this bone. At its insertion, an extra bone can be present and this is termed an accessory navicular.