Foot & Ankle
What is the Normal Anatomy of the Foot and Ankle?
The foot and ankle form complex joints that are involved in movement and providing stability and balance to the body. The foot and ankle consist of 26 bones, 33 joints, and many muscles, tendons, and ligaments.
Bones of the Ankle
The ankle joint connects the leg with the foot and is composed of three bones: the tibia, fibula, and talus. The tibia or shinbone and fibula or calf bone are bones of the lower leg, which articulate with the talus or ankle bone, enabling up and down movement of the foot.
Three bony bumps present on the ends of the tibia and fibula form parts of the ankle joint:
- The medial malleolus, formed by the tibia, is found on the inside of the ankle.
- The posterior malleolus, also formed by the tibia, is found at the back of the ankle.
- The lateral malleolus, formed by the fibula, is found on the outer aspect of the ankle.
Bones of the Feet
The foot acts as a single functional unit, but can be divided into three parts: the hindfoot, midfoot and forefoot.
The hindfoot forms the ankle and heel, and is made up of the talus bone and calcaneus or heel bone. The heel bone is the largest bone in the foot.
The midfoot connects the hindfoot to the forefoot, and consists of one navicular bone, one cuboid bone, and three cuneiform bones. The navicular bone is found in front of the heel bone, and the cuneiform and cuboid bones are arranged in front of the navicular bone.
These bones are connected to five metatarsal bones of the forefoot that form the arch of the foot for shock absorption while walking or running. The forefoot is also made up of the toes or digits, formed by bones called phalanges - three in each toe, except the big toe, which has only two phalanges. The big toe has two additional tiny round sesamoid bones in the ball of the foot, which helps in upward and downward movements of the toe.
Ankle and Foot Joints
There are 33 joints in the ankle and foot. They include:
- Hinge joints in the ankle, which allow flexion (bending) and extension
- Gliding joints found in the hindfoot, which allow gliding movements
- Condyloid joints found in the forefoot and toes, which allow the flexion (bending) and extension, adduction, and abduction (sideward movement).
The joints of the foot and ankle provide stability and support the weight of your body, helping you to walk or run, and adapt to uneven grounds.
Soft Tissues of the Ankle and Foot
Our feet and ankle bones are held in place and supported by various soft tissues such as cartilage, ligaments, muscles, tendons, and bursae.
The joint surface of all the bones of the ankle and foot are lined by a thin, tough, flexible, and slippery surface called the articular cartilage, which acts as a shock absorber and cushion to reduce friction between the bones. The cartilage is lubricated by synovial fluid, which further enables smooth movement of the bones.
Ligaments are tough rope-like tissue that connect bones to other bones, and hold them in place, providing stability to the joints. The plantar fascia is the largest ligament in the foot, originating from the heel bone to the forefoot, it extends along the lower side of the foot and is involved in maintaining the arch of the foot. The plantar fascia ligament stretches and contracts to provide balance and strength to the foot. Lateral ligaments on the outside of the foot and medial ligaments on the inside of the foot provide stability and allow up and down movement of the foot.
The foot is made up of 20 muscles that help in movement. The main muscles include:
- Anterior tibial muscle, which allows up and down movement of the foot
- Posterior tibial muscle, which supports the arch
- Peroneal tibial muscle, which controls movement on the outside of the ankle
- Extensors, which enable the ankle to raise the toes just before stepping forward
- Flexors, which stabilize the toes against the floor
- Smaller muscles that help the toes to lift and curl
Tendons are soft tissues that connect muscles to bones. The largest and strongest tendon in the foot is the Achilles tendon, present at the back of the lower leg around the heel bone. Other tendons include peroneal and anterior and posterior tibialis.
Bursae are small fluid-filled sacs that decrease friction between tendons and bone or skin. They contain special cells called synovial cells that secrete a lubricating fluid.
Midfoot arthritis is pain and inflammation of the midfoot. It occurs due to damage of cartilage or tissues around the joints. The damage may occur due to injury, aging or autoimmunity. The foot bones are the phalanges, the metaphalanges, and the tarsal bones. The midfoot consists of 5 bones called lesser tarsal bones.
Arthritis is inflammation in a joint as a result of cartilage degeneration causing joint pain, swelling, stiffness, and restricted movement. Arthritis of the foot and ankle joint can occur due to fractures, dislocation, inflammatory disease, or congenital deformity.
Arthritis is inflammation in the joint resulting from the degeneration of cartilage causing joint pain, swelling, and stiffness resulting in restricted movements. Arthritis of the foot and ankle joint can occur due to fractures, dislocation, inflammatory disease, or congenital deformity.
Arthritis is the inflammation of joints as a result of degeneration of the smooth cartilage that lines the ends of bones in a joint. This degeneration of the cartilages leads to painful rubbing of the bones, swelling, and stiffness in the joints, resulting in restricted movements.
The tarsometatarsal joint or Lisfranc joint is the region in the middle of the foot formed by the articulation of the tarsal bones (a cluster of seven bones) and metatarsal bones (a group of five long bones). This region supports the arch of the foot. Lisfranc or midfoot fractures are breaks in the bones of the midfoot.
The ankle joint is formed by the articulation of the end of the tibia and fibula (shinbones) with the talus (heel bone). Osteochondral injuries, also called osteochondritis dissecans, are injuries to the talus bone. It is characterized by damage to the bone as well as the cartilage covering it. Sometimes, the lower end of the tibia or shinbone may also be affected.
The Lisfranc joint or tarsometatarsal joint refers to the region in the middle of the foot. It is a junction between the tarsal bones (bones in the foot arch) and metatarsal bones (five long bones in the foot). Lisfranc fractures can occur due to a fall from a height or a traumatic motor vehicle accident.
A sprain is the stretching or tearing of ligaments. Ligaments connect adjacent bones and provide stability to a joint. An ankle sprain is a common injury that occurs when you suddenly fall or twist the ankle joint, or when you land your foot in an awkward position after a jump.
The heel is made up of the calcaneus bone and supported by a network of muscles, tendons, ligaments and soft tissues, which together support the weight of the body and stress during movement. A heel spur is a bony protrusion on the underside of the heel bone, which may not be visible to the naked eye.
Cavus foot also referred to as a high arch, is a condition in which the arch on the bottom of the foot that runs from the toes to the heel is arched more than normal. Because of this, excessive weight falls on the ball and heel of the foot when walking or standing, causing pain and instability.
Bunionette also referred to as a tailor’s bunion is a bony lump that grows on the outside of the foot at the base of your little toe. The deformity got its name as q tailor’s bunion when tailors once sat with their legs crossed all day, with the outside edge of their feet rubbing on the ground.
The Achilles tendon is a strong fibrous cord present behind the ankle that connects the calf muscles to the heel bone. It is used when you walk, run and jump. The Achilles tendon ruptures most often in athletes participating in sports that involve running, pivoting and jumping.
Flatfoot, also known as “fallen arches” or Pes planus, is a deformity in children’s feet where the arch that runs along the sole of the foot collapses to the ground or is not formed at all. Flatfoot is normal in the first few years of life as the arch of the foot usually develops between the age of 3 and 5 years.
Sesamoids are two small, pea-shaped bones located in the ball beneath the big toe joint at the bottom of the foot. Sesamoid bones are connected to muscles and other bones by tendons that envelop these bones. Sesamoids help the big toe move normally and absorb the weight placed on the ball.
Nails are an extension of the top layer of the skin and are composed of a nail plate (top layer) and nail bed (skin below the nail plate). The nail matrix is the region where your toenail begins to grow. Nails are made of keratin (protein) and help to protect your fingers and toes from injury.
The foot is composed of bones, ligaments, nerves, muscles, and tendons. Nerve conditions of the foot can range from minor nerve injuries to serious conditions like nerve entrapment and damage. A podiatrist is a doctor specializing in the treatment of foot problems including nerve conditions.
Claw toe is a deformity where a toe bends and appears like a bird’s claw. The affected toe is bent upward from the joint at the ball of the foot, and downward at the joints in the middle and tip of the toe to curl under the foot. Hard, thick skin called corns may develop under the ball of the foot or on the top of the affected toe, causing pain while walking.
Congenital deformities of the lower limbs are developmental disorders that are present at birth, causing alterations in the shape and appearance of the legs. Several factors such as genetics, teratogenic drugs, and chemicals can cause congenital deformities.
Sever’s disease is a painful inflammation of the growth plate in the heel. Growth plates are areas at the end of children’s bones that undergo changes so bone growth can occur. During this time, the muscles and tendons may not grow as fast as the bone causing tightness and pressure at the back of the heel.
Mallet toe is a deformity where the toe abnormally bends downward, resembling a hammer or mallet. The bones at the tip of the toe are connected by the distal interphalangeal joint (DIP). Muscle imbalance or damage to the tendons or ligaments of the DIP causes contraction and deformity.
Diabetes is a chronic condition that is characterized by high blood glucose (sugar) levels. Diabetic patients are at high risk for developing chronic wounds, especially in the feet. If left untreated, these wounds can cause serious problems that can lead to infections and eventually gangrene, which may require amputation.
The posterior tibial tendon passes through the ankle to attach the calf muscle with the bones of the midfoot. It provides stability to the arch and supports the foot while walking. Inflammation or a tear of this tendon as a result of injury may cause dysfunction, leading to pain and the development of a flatfoot.
Warts are harmless outgrowths on the skin caused by human papilloma virus (HPV) infection. They grow on all body parts including face, fingers, feet, legs, hands, knees, inside your mouth, and on the genital and rectal areas. Plantar warts appear on the bottom or soles of your feet.
Bunionette, also called Tailor’s bunion, is a bony lump formed along the outside of the little toe at the base. It occurs when the very bottom bone (fifth metatarsal bone) of the little toe enlarges or shifts outward. Sometimes, it can be a bony spur (an outgrowth of bone) on the side of the fifth metatarsal bone head.
The tibia and the fibula bones of the lower leg join with the talus bone to form the ankle joint. The talus bone is an important bone located between the tibia and fibula and the heel bone (calcaneus). OCL or OCD is the damage to the cartilage and the talus bone of the ankle joint.
The tarsal tunnel is a narrow passageway that lies on the inside of your ankle and runs into the foot. It encloses arteries, veins, tendons and nerves that supply the foot. The tunnel holds very limited space as it is formed between bones and overlying fibrous tissues. Within the tarsal tunnel lies and runs a nerve called ‘posterior tibial nerve’.
Ankle joint replacement, also known as total ankle arthroplasty, is a surgical procedure performed to relieve pain and immobility due to severe end-stage arthritis that has not responded to non-surgical treatments. The goal of ankle joint replacement surgery is to eliminate your pain and increase the mobility of your ankle joint.
Foot reconstruction is a surgery performed to correct the structures of the foot and restore the natural functionality of the foot that has been lost due to injury or illness. Ideally, any foot surgery for reconstruction is done to improve the appearance and function of the foot so that you can maintain your quality of life.
Minimally invasive bunion surgery, also known as keyhole bunion surgery, is a procedure to treat a foot condition called a bunion or hallux valgus. During minimally invasive bunion surgery, a few small incisions are made to access the bone around the bunion
Minimally invasive foot surgery (MIFS) uses the latest advanced technology to treat foot and ankle pain caused by a variety of conditions. Special surgical instruments, devices, and advanced imaging techniques are used to visualize and perform the surgery through small incisions.
Injuries during sports are common. They can result from accidents, inadequate training, improper use of protective devices, or insufficient stretching or warm-up exercises. Injuries to the foot and ankle are common while playing sports such as football, hockey, skating and in weekend athletes.
Tendons are the soft tissues connecting muscle to bone. The Achilles tendon is the longest tendon in the body and is present behind the ankle, joining the calf muscles with the heel bone. Contraction of the calf muscles tightens the Achilles tendon and pulls the heel, enabling the foot and toe movements necessary for walking, running and jumping.
Foot and ankle fractures are breaks or cracks in any bone of your foot and ankle joint. Fixation of fractures is a surgical method of reconnecting the broken or cracked bones and fixing them in the correct place using orthopedic hardware.
Foot injections are steroids that are injected into your foot to relieve pain and inflammation. Cortisol is a hormone that is produced in the human body and functions to reduce stress and inflammation. Steroids are synthetic drugs that resemble cortisol and are used in treating joint pain.
The foot is composed of different structures including bones, ligaments, tendons, and muscles. As the feet bear the weight of our body, they are more prone to injury and pain. Normally, foot pain can be treated with home treatments but may take time to heal. However, in cases of severe injury, adequate evaluation and treatment is required.