Anatomy, physiology and general conditions of the foot.

Your feet are made for walking – running, jumping, balancing, climbing, and more. Therefore, it is not surprising that the human foot is complex. Believe it or not, your sixth size (or nine or twelve) contains 28 bones, nearly a quarter of all the bones in your entire body, plus 30 joints, and over a hundred muscles, ligaments, and tendons.

All of these structures work together as fine-tuned mechanisms, performing two important functions: weight-bearing and movement. These functions require a high degree of stability. In addition, the foot must be flexible so that it can adapt to uneven surfaces. This is one of the reasons why there are so many bones and joints in each foot.

Here's a quick overview of the structures of the foot and how they work together, as well as some common podiatric problems that sometimes result from normal wear and tear, overuse, or injuries to the foot.

Foot structure

The foot can be divided into three parts: front , middle and rear. Each section contains bones, joints, muscles, tendons, and ligaments.


The bones of the foot can be divided into three categories based on their location.


This is the most advanced part of the foot, including the toes or phalanges. There are a total of 14 toe bones (two for the big toe and three for each of the other four) plus five metatarsal bones.

The first metatarsal bone is the shortest and thickest and plays an important role during movement (forward movement). It also provides attachment to multiple tendons. The second, third, and fourth metatarsals are the most stable of the metatarsals. They are well protected and have only minor tendon attachments.

In addition to the phalanges and metatarsal bones, the forefoot contains two small, oval-shaped sesamoid bones located just below the head of the first metatarsal bone, on the sole or bottom of the foot, which are held in place by tendons and ligaments. . The forefoot connects to the midfoot at five tarsal joints.


This part of the foot is made up of five irregularly shaped bones called tarsals. The clinical names for these bones are scaphoid, cuboid, medial, intermediate, and lateral cuneiform. Together they form the arch of the foot. The arch of the foot plays a key role in stability and stability .

Hind leg

In this part of the foot, there are only two large bones: the talus and the calcaneus. The largest of these, the heel bone, forms the heel of the foot. The talus rests on the calcaneus and forms the ankle joint.


A joint is formed at the junction of two or more bones. Each big toe has two joints: the metatarsophalangeal joint and the interphalangeal joint. The other four toes of each foot have three joints: the metatarsophalangeal joint at the base of the toe, the proximal interphalangeal joint in the middle of the finger, and the distal phalangeal joint, the joint closest to the tip of the finger.


The muscles that control the movement of the foot originate in the lower leg and are attached to the bones of the foot by tendons. These are the main muscles that facilitate the movement of the foot:

  • Posterior tibialis muscle (supports the arch of the foot)
  • Tibialis anterior (allows the foot to move up)
  • Peroneus longus and brevis muscle (controls movement outside the ankle)
  • Extenders (raise your toes so you can take a step)
  • Flexors (stabilizes the toes and flexes them underneath)

Tendons and Ligaments

The most prominent tendon in the foot is the Achilles tendon, which runs from the calf muscle to the heel. It is the strongest and largest tendon structure in the body . The Achilles tendon allows you to run, jump, climb stairs, and stand on your toes.

Other important tendons of the foot include the tibialis posterior (tibialis posterior tendon), which attaches the calf muscle to bones on the inside of the foot and supports the arch of the foot, and the tibialis anterior (tibialis anterior tendon), extending from the external tibia to the first metatarsal bones and surfaces of the medial tarsus in a wedge shape, allowing dorsiflexion, moving the toes towards the lower leg.

These are the main ligaments of the foot:

  • The plantar fascia is the longest ligament in the foot, and the plantar fascia runs along the sole of the foot from the heel to the toes, forming the arch of the foot, providing strength for walking and helping to maintain balance.
  • The plantar calcaneonavicular ligament is the sole of the foot that connects the calcaneus and the navicular and supports the head of the talus.
  • The cuboid calcaneal ligament is the ligament that connects the calcaneus and tarsus and helps the plantar fascia to support the arch of the foot.

Common foot problems

Considering how many moving parts there are in the human foot and how many thousands of miles this incredible body part travels in its lifetime, according to the American Pediatric Medical Association, the average person travels 75,000 miles at age 50, this is not the case. surprisingly, the structures inside can be damaged or overused.

Illustration by Alexandra Gordon, Get Meds Info

And like any part of the body made up of bones, muscles, and connective tissue, the feet are subject to certain conditions that can affect any other limb, limb, or spine, including:

  • Sprains, strains, and traction that affect muscles or ligaments
  • Tendinitis (when a tendon is stretched or torn excessively)
  • Fractures and broken bones.
  • Osteoarthritis (which is especially common in the feet, especially the joints that connect the toes to the midfoot)
  • Rheumatoid arthritis

The legs can also be affected by diseases that are not specific to them, for example:

  • Diabetes
  • Gout (causing uric acid crystals to form in the joint)
  • Infections such as mycosis and onychomycosis (fungal nail infection)

And of course there are problems that are specific only to the foot itself:

Heel spurs

As the largest bone in the foot, the calcaneus is especially prone to injury due to improper biomechanics, such as suboptimal walking. It is common to develop bony formations on the lower part of the calcaneus, called heel spurs, which cause severe pain when standing or walking. Foot dysfunctions, such as heel spurs, are more common in people with plantar fasciitis (inflammation of the fascia on the sole of the foot; see below), flat feet , or high arches of the foot .

Plantar fasciitis

This condition occurs due to microcracks in the thick fibrous tissue at the bottom of the foot, which runs from the heel to the buttocks, caused by excessive stretching. Symptoms include pain in the heel and arch of the foot, which is often worse in the morning. Plantar fasciitis is especially dangerous for runners and long-distance runners .


A bone is a bony bump just below the toe, either on the inner edge of the foot or on the side of the little toe. (The latter is sometimes known as a bunion .) Bursitis forms when the bones of the foot shift, often due to pressure caused by wearing shoes that don't fit or compressing the toes tightly over a long period of time. The big toe can tilt so far inward that it actually crosses over or over the adjacent second toe, causing a secondary displacement called a hammer . Usually a sore callus forms on the top of the second toe.

Fallen bows

Sometimes called flat feet or flat feet, it is a deformity in which the arch of the bottom of the foot straightens, often so completely that the entire foot is in contact with the ground. The result can be pain in the midfoot, swelling of the ankle and arch of the foot, and even pain in the hip, knee, or lower back. A fall in the arches of the foot can be congenital (meaning that a person is born with this condition), but most of the time a flat foot develops as a result of age or injury. 20% to 30% of people suffer from flat feet to one degree or another .

Hammer toe

In this state, the joint in the middle of the toe is permanently curved to the point that it points downward. It develops due to an imbalance in the muscles, tendons, or ligaments that support the straight bones of the toe. As with bursitis and hammer toe, hammer toe often forms as a result of wearing inappropriate shoes, although it can also be caused by injury or some medical condition.


This is the medical name for pain under the sole of the foot. It is often caused by increased pressure on the area from certain types of shoes or conditions such as arthritis, compression of a nerve (called a neuroma; see below), or ligament fractures or tears.

Toe claw

This is a deformity in which the toes bend down from the middle joints or even bend under the foot. Corns or calluses (areas of thickened and inflamed skin) often form on the surface of the affected fingers. Sometimes the callus can put pressure on the nerves in the foot and cause pain.

Morton's neuroma

This is a common problem where compression of a nerve in the ball of the foot causes burning, tingling, and pain around the third and fourth toes. High heels are often the culprit.

Problem diagnosis

To diagnose common problems related to the anatomical structures of the foot, a doctor, usually an orthopedic specialist, examines the outside of the foot for symptoms such as swelling in certain areas and deformities in the shape of the foot, among others. external signs.

However, to make a specific diagnosis, it is usually necessary to look inside the foot with some type of imaging test. A standard X -ray can confirm a bone fracture or arthritic injury. However, if more detail is needed, an orthopedic surgeon will likely want to perform an MRI , a technique that uses a powerful magnet and a computer, or a computed tomography (CT) scan , which creates images by combining multiple X-rays. .

Watch out

As with any medical condition, the treatment of a foot problem will depend on what it is. Obviously, an infection caused by bacteria or fungi will require antibiotics or antifungal medications, for example. Leg pain from any cause can often be relieved with over-the-counter medications such as Tylenol (acetaminophen), Advil, Motrin (ibuprofen), Alev (naproxen), or, for severe discomfort, prescription pain relievers.

For foot problems caused by anatomical deformities, such as a collapsed arch of the foot, orthopedic inserts, which are worn within the shoe to provide optimal cushioning and support for the foot, are often helpful. Standard versions are available in pharmacies and other health stores, but custom-made orthotics are often ordered by the doctor.

In some cases, physical therapy can help improve the strength and flexibility of the feet and ankles. Sometimes fractures and other injuries require surgery , which can finally keep your feet in good shape and ready to travel more miles.

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