The Ankle - Pelvic Girdle

The Ankle

The ankle (tarsus) (see Figure 3.31) consists of the seven tarsal bones: the talus, calcaneus, cuboid,navicular, and the threecuneiforms.

The talus (Figure 3.31C) is the second largest of the tarsals and articulates with the lower end of the tibia and fibula. The superior, lateral, and medial sur-face of the talus appears smooth, as they are part of the ankle joint. The lateral surface has roughened surfaces that indicate the attachment of strong liga-ments that stabilize the joint.

The heel bone, or the calcaneus, is the largest tarsal. The posterior surface of the calcaneus is rough-ened where the tendo calcaneus, or the Achilles ten-don, of the calf muscles is attached. Anteriorly and su-periorly, it is smooth where it articulates with the other tarsal bones. The cuboid and the cuneiforms ar-ticulate with the five metatarsals.

The five metatarsals form the bones of the sole of the foot. They are labeled I to V, proceeding medial to lateral (opposite that of the palm). Each metatarsal, like the metacarpals, has a base, body, and head. Dis-tally, the metatarsals articulate with theproximalphalanges. There are 14 phalanges—each toe hasthree, except for the great toe (hallux), which has two. As in the hand, the phalanges are named proxi-mal, middle, and distal phalanges, according to the position.