There are 26 bones in each foot. These are divided into three distinct groups. The tarsals are located in the heel and ankle, the metatarsals are in the middle of the foot and the phalanges are the bones of the toes. There can also be any number of sesamoid bones in the tendons of the foot.
Tarsals
The tarsal bones are analogous to the carpal bones of the wrist and provide the structure and stability of the heel and ankle. These bones are the tallus, calcaneus, navicular, cuboid and three cuneiform bones. The tibia and fibula of the lower leg articulate with the tallus. The tallus sits atop the calcaneus, which is the large bone in the heel. The navicular bone is at the top of the foot and joins the cuneiform bones to the tallus. The cuboid is on the side of the arch of the foot between the tallus and the fourth and fifth metatarsal bones. The cuneiform bones are between the navicular and the first through third metatarsal on the top of the foot.
Metatarsals
The metatarsal bones are between the tarsal bones and toes (also called phalanges). They are numbered from the inner foot where the great toe is to the outer foot where the little toe is. The metatarsals are long and thin with similar shapes, except for the fifth metatarsal, which has a large wing-like structure where the peroneus brevis tendon attaches near the articulation with the cuboid bone.
Phalanges
The phalanges are the bones of the toes. The great toe has two phalanges and the other toes have three each. These bones are very similar to the bones of the fingers and are actually named exactly the same.
Sesamoid bones are common in the foot, especially on the bottom of the foot where tendons join the bones. These bones form inside tendons where there is extreme stress and help to protect the tendons from damage due to wear and tear and help increase the leverage of a tendon across a joint.
References
- "Gray's Anatomy: The Anatomical Basis of Clinical Practice"; Susan Standring (Editor); 2008
- "Trail Guide to the Body: How to Locate Muscles, Bones and More"; Andrew Biel; 2005
