Bones in the Foot and Ankle
In some ways, the bones in your ankles and feet resemble the bones in your wrist and hand, but instead of carpals and metacarpals, you’ve got tarsals and metatarsals and phalanges in your toes. But your feet certainly are shaped differently from hands because they have a different purpose. Your feet are made for walking, running, standing, and climbing.
The ankle bones
The ankle is the area where the leg attaches to the foot. The distal ends of the tibia and fibula are part of the ankle. The tibia is the larger medial (toward the midline of the body) bone. It has a facet on the distal end that articulates with the talus. The medial malleolus is a projection that you can palpate. It’s the big bump on the medial part of the ankle. The fibula is the slender lateral leg bone. The distal end enlarges to form the lateral malleolus, which is palpated as the large bump on the lateral side of the ankle. The shafts of the tibia and fibula are connected by a thin sheet of connective tissue called the interosseous membrane.
One of the seven tarsal bones, the talus, meets up with the leg bones to form the ankle joint.
The foot bones
The structure of the foot is made by the 6 remaining tarsal bones (other than the talus), the 5 metatarsals, and the 14 phalanges:
Calcaneus bone: The calcaneus is the heel bone, and it’s the largest bone of the foot. The calcaneus comes in contact with the talus at the sustentaculum tali located at the superior and medial part of the calcaneus. The fibular trochlea is located on the lateral part of the calcaneus, and the calcaneal tuberosity is the posterior and inferior portion of the calcaneus (the part of the heel you stand on).
Navicular bone: This boat-shaped bone is found in front of the head of the talus. It has a small tuberosity on its medial side that can be felt about 1 inch in front of and below the medial malleolus of the tibia.
Cuneiform bones: These three bones sit anterior to the navicular bone.
The medial cuneiform is on the medial side of the foot.
The intermediate cuneiform is in between the medial cuneiform and the lateral cuneiform, which is the most lateral.
Cuboid bone: This bone is lateral to the navicular bone and the lateral cuneiform.
A row of five metatarsal bones sits between the tarsals and the bones of the toes. Each one has a head at the farthest end, a shaft, and a base at the closer end. Their names are easy to remember because they’re numbered. The first metatarsal is located on the medial side of the foot between the medial cuneiform and the bones of the big toe. Next are the second, third, fourth, and fifth metatarsals. The fifth metatarsal, which connects to the pinky-toe bones, has a tuberosity that sticks out over the cuboid bone.
The phalanges (singular: phalanx) form the toes. Each one has a base, a shaft, and a head, like the metatarsals, but the phalanges are smaller. The big toe has only two phalanges (proximal and distal), and the remaining toes each have three (proximal, middle, and distal).
Each of your feet has three arches formed by the bones of the foot that help absorb some of the shock of carrying you around all day. The medial and lateral longitudinal arches are between your heel and the ball of your foot, and the transverse arch runs from side to side and is made by the metatarsal, cuboid, and cuneiform bones.