How Does My Foot Work?

How does my foot work?

The human foot is a complex machine consisting of a flexible network of structures including: bones, joints, muscles, tendons and ligaments. Each foot consists of 26 bones, 30 joints and more than 100 muscles/tendons/ligaments all of which work together to provide support, balance and mobility.

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Sections of the foot are divided into three areas:

● The Forefoot: includes the bones of your toes (phalanges) and the five longer bones that attach to them, called metatarsals.

● The Midfoot: consists of a puzzle-like pyramid of bones that contribute to the arches of the feet. These include three cuneiform bones (meaning wedge-shaped), the cuboid bone (square) and the navicular bone which gets its name from being boat-shaped.

● The Hindfoot: contains structures to form the heel and ankle. The talus bone supports the bones of the lower leg (fibula and tibia) to create the ankle. The calcaneus (heel bone) is the largest bone in the foot.

Foot Arches

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What many people don’t realize is that each foot also contains three arches, not just one. When functioning properly, they work the same way as a spring, allowing the feet to bear the weight of the body and absorb the shock produced during activities like walking, running and jumping.

● The Medial Longitudinal Arch: Stretches from the ball of the foot (under the big toe) to the heel. This is what most people think of when discussing ‘the arch of the foot’ because it is the highest and most noticeable arch.

● The Lateral Longitudinal Arch: Spans from the ‘ball’ under the pinky toe to the heel. Note that what we think of as the balls of our feet are actually the heads of the metatarsal long bones where they meet the toes.

● The Anterior Transverse Arch: Crosses the width of the foot from the ball of the foot under the big toe to the ‘ball’ under the pinky toe and represents the arc of the metatarsal heads. All of these structures form an association of moveable parts that work synergistically.

Your feet are your body’s foundation. Our feet provide the groundwork for our upright weight-bearing posture.

This makes them a primary influence when we talk about the kinetic chain in the body. ‘Kinetic chain’ is actually an engineering concept used to describe human movement. It refers to the interconnectedness of the body and how our body areas work together, compensate for or affect one another to perform movements.

Your feet are the starting point for energy absorption and transmission throughout the entire body during any type of movement pattern. Specifically, the source of its power lies is in the arch, which is controlled by a team of muscles, tendons, and ligaments working together in perfect harmony. This team consists of 4 layers of tiny muscles called your intrinsics, strong tendons of the posterior tibialis and peroneal muscles, and your plantar fascia. These structures, in conjunction with the 33 joints in your foot, are dynamic in nature. They are designed to absorb load and convert it into the powerful energy needed for running, jumping, and changing direction.

It has been estimated that every kilogram of body weight exerts up to 1.5 kilograms of force that the feet have to absorb when walking. If a person weighs 90kg, the force on the feet will be up to 272kg. When running, that number grows exponentially with up to 3 kg of force per kilogram of body weight being exerted which would translate to 630kg of pressure per footfall for our 90kg example.

This is especially the case for people with flat feet. Flat feet cause a misalignment with the ankle and can affect your whole body - from the knees to the hips to the spine and neck. Your body will naturally compensate, causing you to walk, sit, and stand in unhealthy ways that may only make the condition worse. Flat feet also don’t have a proper arch to absorb the shock of everyday walking, running, standing, etc. This means that your joints – especially the knees and hips - have to absorb all this shock, even though they aren’t designed to do so. Over time, this added stress can cause severe ankle, knee, and hip malfunction.