Foot Anatomy
Now that we have a better understanding of how our feet evolved into their current form, it is important to become familiar with the various components that make up the foot. Having some basic knowledge of foot structure will help in the understanding of topics covered later.
Even though written descriptions of human body parts can be traced back to ancient Egypt, most anatomical naming conventions can be attributed to the ancient Greeks. Aristotle himself studied the differences in the anatomy of different animal species, making him one of the first to study comparative anatomy. (Crivellato, Ribatti 2007) The story of scientific study and hence scientific naming conventions is a long, complicated one. But generally Latin and early Greek have provided standard scientific vocabulary, at least in the Western world.
Early anatomists described parts of the body by comparing them to familiar objects. For example, the Greek word “phalanx” can be translated broadly as “a body of troops in close array.” Given a little imagination, it makes sense that our Phalanges, or toes, would be referred to in this way.
However, the wide variety of terms and labels for human anatomy can be a barrier when studying anatomy. It is common for anatomical structures to have a Latin name in addition to having been named after “long dead saw-happy French surgeons” (Earls, Wintle 2021) who have made significant contributions to their discovery or understanding, thereby increasing confusion. (See the Lisfranc & Chopart Joints below, for example.) It is for this reason that I have tried to include clear and brief descriptions after each term. I have not included every anatomical aspect of the foot, but only ones that benefit our general knowledge regarding basic foot function and health. After all, this is not a podiatry textbook. But rather a useful tool for understanding our feet from the perspective of the casual reader.
Each bone, muscle, ligament, tendon, and joint in the foot has its specific job, but we can group them into two categories: those that bear the weight of our bodies, and those that propel the body forward. They also function as platforms for stance and shock absorbers for impact. So, it’s no wonder they have such a complex structure.
(REFER TO THE DIAGRAMS AT THE END FOR MORE INFORMATION)
Movements & Positions of the Foot
Let’s define a few terms that we will need to describe how the foot moves and what positions it can take. Follow along and move your foot into each of the positions as they are listed. (Rose, Martorana 2023)
Adduction When the foot moves toward the midline of the body. Think “add”, as in the foot is being “added” to the body as a whole.
Abduction When the foot moves away from the midline. Think “abduction”, as in the foot being abducted or separated from the body.
Dorsiflexion When the ankle bends and the toes are raised upward. The anatomical term “Dorsal” refers to the upper side or back of an animal.
Plantarflexion When the ankle bends and the toes point toward the ground. The anatomical term “Plantar” refers to the bottom of the foot.
Inversion When the sole of the foot turns inward to face the midline.
Eversion When the sole of the foot turns outward to face away from the midline.
Bones
The foot's bones are categorized into three main groups: Phalanges, Metatarsals, and Tarsals. Additionally, the foot can be further divided into three distinct regions: the Forefoot, Midfoot, and Hindfoot. (Rose, Martorana 2023)
Forefoot Bones Helps in push-off during running and walking. Also responsible for balance.
Phalanges The bones in your toes. There are 14: two in the big toe and three in each of the other four toes.
Metatarsals They extend from each toe to the midfoot. The first metatarsal, connected to the big toe, primarily assists in forward movement, while the other metatarsals provide stability to the forefoot.
Sesamoids A sesamoid is a small, round bone that is embedded within a tendon or joint capsule. They are located underneath the first metatarsal bone, where the big toe attaches. They are called the "sesamoids" because their shape resembles a sesame seed. Their role is to provide leverage and assist in weight-bearing activities.
Midfoot Bones
Midfoot bones provide stability and support for the arch of the foot as weight shifts from forefoot to hindfoot.
Navicular A wedge-shaped bone that articulates with five tarsal bones (talus, cuboid, and three cuneiform bones) forming a strong linking joint between them. It is located in the midfoot together with the cuboid and three cuneiform bones.
Cuboid Located near the outside edge of the foot in front of the calcaneus (heel). Plays a role in maintaining foot arch.
Cuneiforms Latin for “wedge”. Located between the metatarsals and the Navicular. Made up of the Medial, Intermediate, and Lateral Cuneiforms. They help shape the arch of the foot.
Hindfoot Bones Absorbs impact and provides a stable platform for standing.
Tarsals Seven bones that make up the structure of the foot rearward of the metatarsals. Below are the two main tarsal bones.
Calcaneus The large bone at the heel of the foot (heel bone). Its main function is to transfer most of the body weight from the legs to the ground.
Talus This is the bone that sits between the calcaneus and the two bones of the lower leg (the tibia and fibula). It distributes weight and pressure through the ankle joint.
Joints
Joints in the body allow bones to glide smoothly against one another when they move. Movement of joints within the foot allows for flexible adaptation to various terrains. Joints enable essential actions such as dorsiflexion (raising toes), plantarflexion (pointing the toes), inversion (sole facing inward), and eversion (sole facing outward). There are 33 joints in the foot. Below are the 5 major kinds. (Rose, Martorana 2023)
Subtalar Joint Allows for eversion and inversion of the foot. The Talus connects to the Calcaneus below it, which is why it is called “Subtalar.”
Transverse Tarsal Joint (Chopart or Midtarsal joint) This joint creates most of the ability of supination and pronation of the foot. This movement is like inversion/eversion but in 3 directions, as opposed to strict planar motion in two directions.
Metatarsal Phalangeal Joint There are five metatarsal-phalangeal joints where the metatarsals of the foot connect with their corresponding phalanges (toes).
Interphalangeal Joint The joints that connect the phalanges (toes).
Tarsometatarsal Joints (Lisfranc joints) connect the tarsal and metatarsal bones and provide stability to the arch of the foot.
Muscles
The 100 muscles in the foot are responsible for generating movement and maintaining stability. These muscles can be divided into intrinsic and extrinsic groups. Intrinsic muscles start and end in the foot. Extrinsic muscles start outside of the foot in the leg and end in the foot. (Ficke, Byerly 2023)
Tibialis Posterior (extrinsic) Supports the arch of the foot.
Tibialis Anterior (extrinsic) Allows the foot to move up and the ankle to roll outward (dorsiflexion and inversion).
Peroneus Longus & Brevis (extrinsic) Tilts the sole of the foot away from the midline of the body (eversion) and extends the foot downward (plantar flexion).
Extensors (intrinsic) Raise the toes when stepping.
Flexors (intrinsic) Stabilize the toes and curl them under.
Ligaments & Tendons
Ligaments and tendons are soft, fibrous connective tissues that help joints function. Ligaments attach to bones and tendons attach muscles to bones. (Ficke, Byerly 2023)
Tendons
Achilles tendon A very well-known tendon of the foot that runs from the calf muscle to the heel. It is the strongest and largest tendon in the body that makes it possible to run, jump, climb stairs, and stand on your toes.
Tibialis posterior This tendon attaches the calf muscle to the bones on the inside of the foot and supports the foot arch.
Tibialis anterior This runs from the outer bone of the lower leg to the bones in the ankle area and first metatarsal, which enables dorsiflexion.
Ligaments
Plantar fascia The longest ligament in the foot, running from the heel to the toes, supporting the foot's arch and providing strength for walking and balance.
Plantar Calcaneonavicular This is a ligament that connects the calcaneus to the talus. It supports the head of the talus.
Calcaneocuboid This is the ligament that connects the calcaneus to the tarsal bones. It helps the plantar fascia support the arch of the foot.
Nerves
The nerves of the foot originate at your spine and branch off to travel through your buttock and down your leg. (Ficke, Byerly 2023)
Tibial nerve This nerve includes the medial plantar nerve and the lateral plantar nerve, which supply feeling to the sole of the foot. It also includes the sural nerve, which gives feeling to the outside of the foot.
Peroneal nerve This nerve includes the deep peroneal nerve and the superficial peroneal nerve, which provide feeling to the web space between the first and second toes as well as helps the ankle move.
Saphenous nerve This nerve branches off the femoral nerve and provides feeling to the inside of the foot.
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