The navicular bone is a small bone found in the feet of most mammals. The navicular bone in humans is one of the tarsal bones, found in the foot. Its name derives from the human bone's resemblance to a small boat, caused by the strongly concave proximal articular surface. The term navicular bone or hand navicular bone was formerly used for the scaphoid bone, one of the carpal bones of the wrist. The navicular bone in humans is located on the medial side of the foot, and articulates proximally with the talus, distally with the three cuneiform bones, and laterally with the cuboid. It is the last of the foot bones to start ossification and does not tend to do so until the end of the second year in girls and the beginning of the fourth year in boys, although a large range of variation has been reported. The tibialis posterior is the only muscle that attaches to the navicular bone. The main portion of the muscle inserts into the tuberosity of the navicular bone. An accessory navicular bone may be present in 2-14% of the general population.