The Bones of the Foot
The bones of the foot can be divided into three groups: the tarsus, the metatarsals, and the phalanges (
The tarsus (from an old Greek word for the ankle) is a group of seven bones that have a limited amount of movement between them as their flat surfaces slide against each other. Otherwise, they can be thought of as a fairly solid mass. The largest forms of this mass are the talus (
slope), which contacts the tibia and fibula to form the joint of the ankle, and the calcaneus (
cal-KAY-nee-us, from an old Latin word for the heel), which is shaped like a hammer pointing posteriorly; this is the heel bone.
Each of these bones has a capping bone. For the talus, this is the navicular (
navy) bone. For the calcaneus, it is the cuboid (
Three bones sitting on the navicular bone are the cuneiform (
wedge-shaped) bones, numbered from one to three from the medial to the lateral side. The distal surface of Cuneiform 1 is roughly the midpoint of the length of the foot. Cuneiform 3 borders the cuboid bone.
The next rank of bones is the metatarsals. A bit of a reversal of terminology occurs here. For the rest of the long bones, the head of the bone is on the proximal end. For the metatarsals, the head is on the distal end; the proximal end is the base. Conceptually, the metatarsals are seen to be growing out of the tarsus, with their roots at the bases.
The last rank is that of the phalanges.
Phalanges is plural for phalanx (
FAY-lanks), which refers to the orderly rows of infantry used by the Greeks. These are the bones of the toes. The big toe consists of two phalanges; the others, even the little toe, have three. The major joint in the foot is here between the bases of the phalanges and the heads of the metatarsals.