Guide to Foot Anatomy
The foot is an intricate structure of 26 bones, 33 joints, and over 100 muscles, tendons, and ligaments that provide support, balance, and mechanical function. In fact, the bones of the feet account for 25% of the total bones in the entire human body. Add to this the constant stress, impact, and pressure that the feet endure on a daily basis and there is the potential for many foot problems to arise over the course of a lifetime of activity. If one part of the foot lacks proper placement or function, it can affect the entire foot, as well as other parts of the body.
The Parts of the Foot
The basic foot structure is comprised of three sections:
- Forefoot: The forefoot area includes the five phalanges and their connecting metatarsals, as well as the ball of the foot. The phalanges are the toes, and the metatarsals are the long bones that connect to the phalanges. The big toe has two bones and one joint; the four smaller toes each have three bones and two joints.
- Midfoot: The midfoot area is the arch, which is formed by five tarsal bones. The plantar fascia ligament runs along the arch, connecting the midfoot to the forefoot and hindfoot, along with other muscles.
- Hindfoot: The hindfoot area connects the midfoot and ankle and is made up of three joints, as well as the heel bone. The heel is the largest bone in the foot and is protected by a fatty pad that absorbs shock and reduces pressure. Where the hindfoot and ankle meet, the joints form a hinge that allows for up and down motion of the foot.
Malformations & Foot Deformities
Some of the most common reasons for foot and ankle problems are injuries; congenital foot deformities that occur at birth and can be hereditary; infections (bacterial, fungal, or viral); arthritis affecting one or multiple joints; tumors and abnormal growths; and issues that arise from ill-fitting or improper footwear, stress, or mechanical changes.