Foot and Ankle Anatomy | Dr. Gary Driver

The complex structures of the foot and ankle allow us to move, balance, and support our body weight. With an intricate network of 26 bones, 33 joints, and a range of muscles, tendons, and ligaments, every component of the foot works to maintain mobility, strength, and stability. Understanding foot and ankle anatomy offers insight into how these vital body parts work and can help prevent injuries by enabling you to spot potential issues early and take proactive steps to maintain foot and ankle health.

Bones of the Foot and Ankle

Here are the bones of foot and ankle that provide the foundation for mobility and balance:

Ankle Bones

The ankle bones connect the lower leg to the foot. They help transfer weight from the leg to the foot and allow smooth movement while walking, running, and jumping. The ankle is categorized into two main parts: the lower and upper ankle. The upper ankle works to support upward and downward foot movement while allowing a little movement to the side. The lower ankle works to allow inward and outward foot movement. The ankle consists of three bones:

Talus: This ankle bone supports body weight and fosters smooth movement by connecting with the shinbone and calf bone.
Tibia: The tibia, commonly known as the shinbone, is the largest bone in the lower leg and forms the inside part of the ankle. It connects muscles, ligaments, and tendons in the ankle to the rest of the body and helps stabilize movement.
Fibula: This bone forms the outer part of the ankle. Its main function is to offer structural support to your leg.

Foot Bones

The foot is categorized into three major parts: the hindfoot, midfoot, and forefoot. These parts work together as a single unit to help you move smoothly and maintain balance. The hindfoot consists of the talus and calcaneus bones, which form the ankle and heel. It connects with the midfoot, which is made up of the navicular, cuboid, and cuneiform bones. These midfoot bones connect to the five metatarsal bones of the forefoot. This part of the foot forms the arch for shock absorption during foot movement. The forefoot also includes the toes, which are made up of phalanges that help with dexterity, balance, and stability.

Joints of the Foot and Ankle

These are the joints that make up the foot and ankle:

Talocrural Joint

The talocrural joint, commonly called the ankle joint, is where the tibia, fibula, and talus meet. This joint connects the foot to the lower leg and acts as a hinge, enabling up and down movement of the foot. It helps in walking, running, and jumping and supports the weight of the body. The talocrural joint also consists of ligaments that provide stability and protect the joint from strain due to excessive movement.

Subtalar Joint

The subtalar joint is situated right below the ankle joint, where the calcaneus connects with the talus. It is made up of a network of bones and ligaments. This joint allows side-to-side and rotational movements of the foot, helping you to adjust to uneven surfaces and maintain balance.

Tarsometatarsal Joints

The tarsometatarsal joints connect the tarsal bones in the midfoot to the metatarsal bones in the forefoot. They work by transferring weight from the ankle to the toes, helping with stability and flexibility. Together, they form an S-shape and are divided into three different columns:

Medial Column: Made up of the first metatarsal and medial cuneiform
Middle Column: Made up of the second and third metatarsals and lateral and intermediate cuneiforms
Lateral Column: Made up of the fourth and fifth metatarsals and the cuboid

Metatarsophalangeal Joints

The metatarsophalangeal joints connect the metatarsal heads with the bases of the phalanges. Commonly known as toe knuckles, they are supported by numerous ligaments, including collateral, plantar, and deep traverse metatarsal ligaments. These joints play a pivotal role in offering stability and dexterity while walking. They enable flexion, abduction, extension, and adduction movements.

Muscle Groups of the Foot and Ankle

The foot and ankle are associated with 34 muscles, which enable movement and give the foot and ankle their shape. Some of the major muscles and muscle groups that support the foot and ankle include:

Anterior Tibialis Muscle

This muscle runs along the front of the lower leg. It originates from the upper portion of the tibia and attaches to the first cuneiform and metatarsal bones in the foot. It enables upward bending and internal rotation of the foot. The main function of this muscle is to stabilize the ankle during any activity that requires foot motion. It helps maintain balance so that you can walk smoothly, even on uneven ground.

Posterior Tibialis Muscle

The posterior tibialis muscle is located deep within the back of the lower leg. It plays a role in stabilizing the arches of the feet, enabling the downward bending of the foot, and enabling the foot to rotate inwards. Any weakness or injury to this muscle can cause flat feet or issues with arch control in adults.

Peroneal Muscles

The peroneal muscles, also known as fibular muscles, originate from the fibula and run down the outer side of the lower leg. These muscles stabilize the ankle and foot and enable external rotation and downward bending of the foot. They also provide support for the arches of the feet. Strengthening these muscles can improve balance and reduce the chances of injury during physical activity.

Calf Muscles

The calf muscles contribute to ankle and foot mobility by allowing up and down movement. They are situated on the back of the lower leg, originating below the knee and extending to the heel. The calf muscles are responsible for helping you stand up straight and providing support for the foot and ankle during high-impact activities like running and jumping.

Extrinsic Foot Muscles

Extrinsic foot muscles are those that originate in the lower leg and control larger movements of the feet. These muscles provide strength for foot mobility and are responsible for external rotation, internal rotation, upward bending, and downward bending of the foot. They include the soleus, gastrocnemius, tibialis anterior, tibialis posterior, peroneal muscles, extensor muscles, and flexor muscles.

Intrinsic Foot Muscles

Intrinsic foot muscles originate within the foot and are responsible for fine motor movements and stability. Their primary function is to support the arches, control toe motion, and distribute weight evenly throughout the foot. These muscles are divided into two categories: dorsal intrinsic foot muscles and plantar intrinsic foot muscles. They consist of a vast network of muscles, including the abductor hallucis, flexor digitorum brevis, quadratus plantae, lumbricals, dorsal interossei, and plantar interossei.

Tendons of the Foot and Ankle

The tendons in the foot and ankle are bands of tissue that attach muscles to bones to enable movement and shock absorption. Some of the main tendons in the foot and ankle include:

Achilles Tendon

This is the strongest and largest tendon in the human body which connects the calf muscle to the heel bone. It begins in the lower calf, runs along the back of the ankle, and inserts at the back of the heel. This Achilles tendon enables walking, jumping, and climbing.

Posterior Tibial Tendon

This tendon connects the posterior tibialis muscle to the navicular bone and adjacent cuneiforms in the midfoot. It runs along the inner side of the lower leg behind the inner ankle bone and extends under the foot to support the medial arch. This tendon helps invert the foot and supports proper alignment of the foot and ankle.

Peroneal Tendons

The peroneal tendons consist of two primary tendons: the peroneus brevis and the peroneus longus. They are located on the outer side of the lower leg and ankle. These tendons work together to stabilize the ankle during movement and prevent sprains. Some common injuries associated with these tendons include peroneal tendonitis, peroneal tendon tears, and peroneal tendon subluxation.

Ligaments of the Foot and Ankle

Ligaments are bands of tissue that connect bone to bone. Dozens of ligaments in the foot and ankle join bones to form joints and give your foot and ankle their structure. They include the following:

Ankle Ligaments

The ankle ligaments are strong connective tissues that stabilize the ankle joint, control movement, and prevent the ankle from twisting. They are present on both sides of the ankle and help absorb the shock of movement. Ankle ligaments are divided into lateral, medial, and syndesmotic ligaments, each with different functions.

Lateral Ligaments: These are located on the outer side of the ankle and prevent it from twisting, folding, or collapsing. They originate at the end of the fibula and connect with the talus and calcaneus. They include the anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament, each serving a specific purpose.
Medial Ligaments: These are located on the inner side of the ankle, originating from the end of the tibia and extending to the talus, calcaneus, and navicular bones. They consist of four ligaments: the anterior tibiotalar ligament, posterior tibiotalar ligament, tibiocalcaneal ligament, and tibionavicular ligament.
Syndesmotic Ligaments: These ligaments establish a connection between the tibia and fibula bones. They include five main ligaments that function to stabilize the bones and maintain proper alignment during physical activity.

Foot Ligaments

The foot ligaments are responsible for maintaining the arches, stabilizing joints, and enabling smooth movement. Some of the primary ligaments in the foot include:

Plantar Ligaments: These include the plantar fascia and long plantar ligament, which support the arch of the foot and absorb shock during movement. They connect bones in your foot and give structure to the arch of the foot.
Calcaneocuboid Ligament: This ligament connects the tarsal bones and heel bone. Its main function is to support the arches of the foot.
Lisfranc Ligaments: These ligaments are located in the midfoot under the Lisfranc joint. They stabilize the arch of the foot and distribute weight evenly across the foot during movement.

Why Understanding Foot and Ankle Anatomy Is Important?

Understanding the intricacies of foot and ankle anatomy can help you prevent injuries. The bones, muscles, tendons, and ligaments work in unison to make sure your feet and ankles function smoothly. Weakness or injuries in any of these parts may lead to discomfort and disrupt your daily life. If you are experiencing persistent discomfort in your foot or ankle, consider booking an appointment with Dr. Gary Driver. He will provide you with an accurate diagnosis and tailored treatment to help you regain mobility.

Frequently Asked Questions

How many joints are in the foot?

Your foot is made of 33 joints. These joints are connected to a network of muscles, ligaments, and tendons that work collectively to ensure foot functionality.

How do the arches of the feet support movement and balance?

The arches of the feet support movement and balance by acting as shock absorbers. They help distribute body weight evenly throughout the foot and minimize strain on joints and muscles.