Foot bones. Coloured X-ray of the bones in a healthy human left foot, seen in top view. At bottom is the largest bone of the foot, the calcaneous, which forms the heel projection behind the foot. At lower right is the talus bone which forms the ankle joint of the foot and which arti- culates with the tibia (not seen) of the leg. The calcaneous and talus bones form joints with the cuboid (lower centre left) and navicular (lower centre), and the navicular with three cuneiform bones (centre). Five long metatarsal bones (upper centre) form the base of the toes. The phalanges bones (at top) form the toes themselves, two bones in the big toe, and three bones in the other toes.