Anatomy of the Foot

The anatomy of the human foot comprises one or more bone segments, inclusive of nails. This integral part of the human anatomy enables movement from one place to another, and carries the body weight around. The human foot is plantigrade in structure. The major bones in the skeletal anatomy of the foot include:

• Phalanges or toe bones, calcaneus or the heel bone, and the cuboid for balance.
• Metatarsals or the bony frames, navicular bone behind the cuneiforms, and sesamoid bones for locomotion.
• Three cuneiforms between the navicular and metatarsal bones and the talus, or the ankle bone, for maneuvering direction.

Research in anthropometrics reveals that the mean foot length is around 26 cm. There could be a deviation by approximately a centimeter either way. The anatomy of the human foot is synonymous with mechanical complexity. The appendage enables smooth body movement and helps us maneuver the body mass in the desired direction. The foot is associated with structural strength and is designed to sustain exposure to the enormous external pressure on the body. The ankle, heel and toes are the body's shock absorbers, that also run the propulsion processes and framework. The feet, together provide the human body with flexibility and support. The resiliency of this appendage is the result of the coordination of a structure that comprises 26 bones and 33 joints.

The foot facilitates mobility and balance through synchronized movements of more than a hundred muscles, ligaments, and tendons. These fibrous tissues connect the bone and muscle mass, encasing a network of nerves, blood vessels, and soft tissue. The movements of the foot are the result of excellent coordination between all these structural components. Together, they provide the human body with the power to relocate body weight. Structurally, the human foot comprises the forefoot, mid-foot and hind-foot.

Forefoot: This segment of the human foot refers to the bone and muscle structures around the five toes or phalanges, and metatarsals. Each toe or phalanx comprises a number of smaller bones. The hallux, or big toe, has two phalanx, distal and proximal, and one interphalangeal joint. The other four toes have three bones and two joints each. The forefoot bears more than half of the body weight.

Mid-foot: The mid-foot comprises five tarsal bones that are irregularly shaped. This foot segment functions like a shock absorber. The bones of this foot segment are connected to the structures of the forefoot and hind-foot by the plantar fascia ligament framework.

Hind-foot: The hind-foot connects the mid-foot to the ankle bone. It is composed of three joints that form a sort of hinge. This structure enables the up and down movement of the appendage.

The main foot muscles include:

• Anterior tibial for upward maneuvers.
• Posterior tibial for foot-arch support and to bear body weight.
• Peroneal tibial to control ankle movement.
• Extensors to enable forward movement.
• Flexors to stabilize toes against ground surface.

The anatomy of the foot also comprises the Achilles tendon that runs the length of the calf muscle to the heel. The flexibility and strength of this tendon facilitates walking, running, jumping and raising the body weight onto the toes. The plantar fascia stretches and contracts to provide balance and additional foot strength whenever required. The skeleton of the human foot is consistently exposed to a number of deformities and disabilities, like arthritis, gout, flatfoot and talipes.