Anatomy and Physiology of the Foot
The forefoot includes the five metatarsal bones, and the phalanges (the toes). The first metatarsal bone bears the most weight and plays the most important role in propulsion. It is the shortest and thickest. It also provides attachment for several tendons. The second, third, and fourth metatarsal bones are the most stable of the metatarsals. They are well protected, have only minor tendon attachments, and are not subjected to strong pulling forces.
Near the head of the first metatarsal, on the plantar surface of the foot, are two sesamoid bones (a small, oval-shaped bone that develops inside a tendon, where the tendon passes over a bony prominence). They are held in place by their tendons and are also supported by ligaments.
The midfoot includes five of the seven tarsal bones (the navicular, cuboid, and three cuneiform). The distal row contains the three cuneiforms and cuboid. The midfoot meets the forefoot at the five tarsometatarsal (TMT) joints. There are multiple joints within the midfoot itself. Proximally, the three cuneiforms articulate with the navicular bone.
The skeleton of the foot begins with the talus, or ankle bone, that forms part of the ankle joint. The two bones of the lower leg, the large tibia, and the smaller fibula, come together at the ankle joint to form a very stable structure known as a mortise and tenon joint. The mortise and tenon structure is well known to carpenters and craftsmen who use this joint in the construction of everything from furniture to large buildings. The arrangement is very stable.
The two bones that make up the back part of the foot (sometimes referred to as the hindfoot) are the talus and calcaneus, or heel bone. The talus is connected to the calcaneus and the subtalar joint. The ankle joint allows the foot to bend up and down. The subtalar joint allows the foot to rock from side to side.
Ligaments and Tendons
The large Achilles tendon is the most important tendon for walking, running, and jumping. It attaches the calf muscles to the heel bone to allow us to push off and up on the toes. There are another 12 tendons that cross the ankle. They are responsible for movements of the ankle, foot, and toes; some of these tendons also help support the arches of the foot.
Muscles
The muscles of the foot are classified as intrinsic and extrinsic. The intrinsic muscles are located within the foot and cause movement of the toes and act as flexors (plantar flexors), extensors (dorsiflexors), abductors, and adductors of the toes. Several intrinsic muscles also help support the arches of the foot.
The extrinsic muscles are located outside the foot, in the lower leg. The gastrocnemius muscle (calf) is the largest. They have long tendons that cross the ankle to attach to the bones of the foot and assist movement.
Summary
By learning more about our foot anatomy, we can better understand how to prevent and treat symptoms associated with it. When foot injuries are present, whatever is required depends on the area affected and the symptoms present, and that is why it is important to have a team of doctors that is able to identify the root cause.
At BBC Health in Lewisville, Texas, we know how to identify, treat, or refer in the proper direction for any problems with your feet. As a primary care provider, we can quickly provide medical, chiropractic, and rehab treatments in order to get you well as fast as possible. If you’re suffering from foot pain, don’t delay, and contact us immediately to see how we can help.
