What to know about foot anatomy

Share on Pinterest

In the foot, there are:

• 26 bones
• 33 joints
• more than 100 muscles, tendons, and ligaments

Bones of the foot

The bones in the foot make up nearly 25% of the total bones in the body, and they help the foot withstand weight.

Experts often classify the bones of the foot into three groups, though they may do so in slightly different ways. Generally, the three groups are the:

• tarsals
• metatarsals
• phalanges

Tarsals

The tarsals are a group of seven bones close to the ankle.

The proximal tarsal bones are the talus and the calcaneus, which is the largest bone of the foot.

The talus is on top of the foot and forms a joint with the tibia and fibula, of the lower leg.

The calcaneus is underneath the talus and forms the heel bone.

There is also one intermediate tarsal (the navicular) and four distal tarsals (the cuboid, lateral, intermediate, and medial cuneiform bones).

Metatarsals

The metatarsals come next, moving distally away from the ankle toward the toes.

The metatarsals lie in a row. Experts number them 1–5, from the big toe to the outer edge of the foot.

Phalanges

Finally, there are the 14 phalanges, or the toe bones, of each foot. There are two in the big toe and three in each of the other toes.

Joints of the foot

Joints are moveable connections between the bones of the body.

Everywhere bones meet is a joint. For example, the big toe has two joints, and the other toes have three.

A layer of cartilage covers bone surfaces in joints so that they can move smoothly over each other. A capsule filled with a lubricating fluid encapsulates the bone surfaces within the joints.

Muscles of the foot

The 29 muscles of the foot allow movement, maintaining normal gait, shape, and posture.

There are 19 intrinsic muscles, which are muscles contained and acting wholly within the foot. These are mainly for fine motor control, such as toe movements.

The 10 extrinsic muscles of the foot cross the ankle joint to connect with the leg.

Tendons and ligaments of the foot

Ligaments attach bones to other bones at joints, and there are more than 30 in the foot. Tendons attach muscles to bone, so they are important for controlling movement. Both are tough, fibrous lengths of connective tissue.

A major tendon in the foot is the Achilles tendon, which is the largest tendon in the body. It runs from the muscles of the calf to the calcaneus and plays a role in many movements — such as running, walking, and climbing stairs — by helping lift the heel from the ground.

The longest foot ligament is the plantar fascia, which runs underneath the foot connecting the heel to the toes, forming the arch. It helps with balance and strength.

Because the foot is such a complex structure, there are many different conditions that can affect it. The sections below will explore some of the most common.

Plantar fasciitis

Plantar fasciitis causes pain in the heel or back of the arch. It is very common, affecting around 2 million people in the United States.

Plantar fasciitis is a chronic condition. Experts believe that inflammation of the plantar fascia causes it, though there is now some evidence for degeneration of the tissue being involved.

There are a range of treatment options for this condition, including:

• taking nonsteroidal anti-inflammatory drugs (NSAIDs)
• resting
• applying ice
• using cushioned, supportive shoes or inserts
• using a splint that stretches the plantar fascia overnight
• stretching and undergoing physical therapy
• receiving injections of a cortisone steroid

Heel spurs

Heel spurs are a type of bone spur. Bone spurs are bony growths that form along the edges of bones.

They can occur in different parts of the body, including the heels, where they cause pain when standing or moving on the bottom of the foot.

Treatment options include:

• resting
• undergoing physical therapy
• taking NSAIDs
• receiving corticosteroid injections
• undergoing surgery

Bunions

A bunion is a bony lump that forms in the big toe joint, where the metatarsal meets the first of the phalanges. They are more common in women.

Bunions are small at first but usually grow larger, causing inflammation and other problems, which can lead to difficulties with walking.

Wearing tight, narrow shoes can cause bunions, as can conditions such as rheumatoid arthritis. A person can also inherit certain types of bunions.

Treatment options include:

• wearing shoes with more toe room
• using pads to help cushion the bunion, though they need to be the right size
• using shoe inserts, toe spacers, and night toe splints
• taking NSAIDS
• icing the toe
• undergoing surgery

Achilles tendon injuries

The large Achilles tendon can become inflamed, causing pain and swelling. This is usually as a result of repetitive stresses, rather than a one-off incident.

Doctors call this condition tendinitis, and it can progress to tendonosis, wherein the structure of the tendon starts to break down and tiny tears appear.

Treatment options include:

• wearing a cast or boot to reduce the force going through the tendon
• taking NSAIDs
• undergoing physical therapy
• applying ice
• using shoe inserts to correct gait, which can be a contributing factor
• using night splints
• undergoing surgery

In contrast, the Achilles tendon can completely or partially tear as a result of jumping or falling, for example.

Achilles tendon injuries are more likely to require surgery to repair the tear and prevent rerupture.

The foot is a complex structure that has many parts. Therefore, many different conditions can affect it.

Many of these conditions can resolve with simple self-care strategies. Sometimes, however, healthcare professionals may recommend surgery or the use of orthotic devices.