The Three Arches of the Human Foot: How They Work Together
22 October 2026
By Mark Reyneker, BTech (Podiatry), MSc (Palaeontology), Registered Podiatrist, Foot & Gait Specialist | Founder & Clinical Director, Family Podiatry Centre
Published: 21 October 2026 | Last reviewed: 21 October 2026
Most people are familiar with the arch along the inside of their foot. However, the human foot actually has three interconnected arches:
- Medial longitudinal arch (MLA) – runs along the inside of the foot.
- Lateral longitudinal arch (LLA) – runs along the outside of the foot.
- Transverse arch (TA) – curves across the width of the foot, particularly through the midfoot.
These arches are formed by the shape and arrangement of the foot bones, supported by ligaments, tendons, muscles and the plantar fascia. Together, they create a remarkable three-dimensional structure that supports body weight, distributes forces and adapts to movement.
Modern research has revealed that the shape of the bones, particularly the transverse curvature of the midfoot, makes an important contribution to the foot’s mechanical properties. The three arches are not rigid structures that must remain elevated. They are designed to move and change shape as we stand, walk and run.
Modern research has revealed that the shape of the bones, particularly the transverse curvature of the midfoot, makes an important contribution to the foot’s mechanical properties. The three arches are not rigid structures that must remain elevated. They are designed to move and change shape as we stand, walk and run.
Your Foot Has Three Arches, Not Just One
Take a moment to look at the inside of your foot. You will probably notice a curved space between your heel and the ball of your foot. This is the arch that most people recognise. But what about the outside of your foot? And did you know that another arch runs across the width of your foot?
The human foot contains 26 bones, connected through numerous joints, ligaments and tendons. These bones are not arranged in a flat structure. They form a complex three-dimensional architecture consisting of three principal arches.
Each arch has its own anatomical characteristics, but none functions in isolation. Together, they allow the foot to perform two very different tasks: support substantial loads while also remaining mobile enough to accommodate the changing demands of movement. To appreciate how this works, we need to look at each arch individually.
1. The Medial Longitudinal Arch: The Arch Everyone Knows
The medial longitudinal arch (MLA) is the most recognisable arch of the human foot. It extends along the inner side of the foot, from the heel towards the first three metatarsals.
Which bones form this arch?
Which bones form this arch?
The medial longitudinal arch is formed by the:
- Calcaneus (heel bone)
- Talus (ankle bone)
- Navicular
- Three cuneiform bones
- First, second and third metatarsals
The way these bones are shaped and arranged creates the characteristic curve visible along the inside of the foot. The talus and navicular occupy important positions in this architecture. Although the arch is commonly illustrated as a simple curve, it is actually a series of interconnected bones and joints, each contributing to the overall structure.
What does the medial longitudinal arch do?
The medial arch supports weight and changes shape as forces pass through the foot. When you stand, your body weight loads the foot and the arch may lower slightly. During walking, its height and length change as the foot makes contact with the ground and progresses through each step. These movements are normal.
The medial arch also works with the plantar fascia, ligaments and muscles to manage mechanical forces and contribute to the storage and return of elastic energy. It is therefore misleading to think that the medial arch must remain in a fixed, elevated position. An important characteristic of the medial arch is its ability to deform under load while maintaining sufficient mechanical resistance to perform its functions.
The medial arch also works with the plantar fascia, ligaments and muscles to manage mechanical forces and contribute to the storage and return of elastic energy. It is therefore misleading to think that the medial arch must remain in a fixed, elevated position. An important characteristic of the medial arch is its ability to deform under load while maintaining sufficient mechanical resistance to perform its functions.
2. The Lateral Longitudinal Arch: The Arch Most People Never Notice
The lateral longitudinal arch (LLA) is located along the outside of the foot. It extends from the heel towards the fourth and fifth metatarsals. Unlike the medial arch, the lateral arch is much lower.
This explains why the outside border of the foot commonly makes contact with the ground when standing. Which bones form the lateral arch?
The lateral longitudinal arch consists primarily of:
- Calcaneus
- Cuboid
- Fourth metatarsal
- Fifth metatarsal
The cuboid plays an important role in the structure of the lateral column. Its shape and orientation, together with the calcaneus and lateral metatarsals, create the relatively shallow curve of this arch.
What does the lateral arch do?
The lateral longitudinal arch contributes to the foot’s supporting surface and the transmission of forces between the heel and forefoot. Compared with the medial arch, it has traditionally been considered a relatively stable part of the foot. However, the lateral arch is not immobile.
The joints of the lateral column permit movements that help the foot respond to changing loads and walking surfaces. Although we describe the medial and lateral arches separately, they are mechanically connected through the bones and joints of the foot. Movement and loading in one region can influence the other. The lateral arch is just as much a part of normal foot architecture as the more prominent arch on the inside.
3. The Transverse Arch: The Hidden Arch That Makes a Big Difference
The transverse arch (TA) is perhaps the most interesting of the three because it is not easily visible when looking at the foot from the side. Instead of running from heel to toe, it curves across the width of the foot. Its important structural curvature is found in the midfoot, involving the cuneiform bones, cuboid and bases of the metatarsals.
Where is the transverse arch?
Imagine looking at a cross-section of the foot through the middle of the tarsal bones. Rather than finding the bones arranged in a straight, horizontal line, you would see that their shapes and positions create a curved arrangement. This forms the transverse arch.
The configuration is particularly important because it contributes to how the foot resists bending along its length. An important distinction: The transverse arch is not simply a raised space beneath the ball of the foot
Some traditional illustrations show the transverse arch extending across the metatarsal heads, with the middle metatarsals suspended above the ground. However, the central metatarsal heads normally participate in weight-bearing and often carry substantial plantar pressures.
Consequently, the transverse arch should not be understood simply as an empty space beneath the middle of the forefoot. The transverse curvature through the midfoot is particularly significant when discussing the mechanical stiffness of the foot.
Why does the transverse arch matter?
Here is a simple way to understand its function. Imagine holding a sheet of paper horizontally. When the paper is flat, it bends easily. Now curve the paper across its width.
Suddenly, the paper becomes more resistant to bending along its length, even though the paper itself has not changed. Its shape has changed its mechanical behaviour. A similar principle applies to the human foot.
Suddenly, the paper becomes more resistant to bending along its length, even though the paper itself has not changed. Its shape has changed its mechanical behaviour. A similar principle applies to the human foot.
In 2020, researchers led by Madhusudhan Venkadesan published an important study in Nature examining the transverse arch. They found that transverse curvature, working through the tissues connecting the metatarsals, made a substantial contribution to longitudinal foot stiffness.
In their experimental models, this contribution exceeded 40%. This does not mean that the transverse arch always accounts for 40% of stiffness during everyday walking. The figure refers to the mechanical conditions studied.
Nevertheless, the research demonstrated an important principle: The curvature of the foot across its width helps determine how strongly it resists bending along its length. This highlights something that is easily overlooked: the shape of the foot bones contributes directly to foot function.
4. What Actually Holds the Three Arches Together?
If the arches are formed by bones, what prevents those bones from simply moving apart when we stand on them? The answer involves several anatomical systems working together.
The bones provide the architecture
The size, shape and orientation of the foot bones determine the basic three-dimensional structure. Certain bones have wedge-like shapes, while their joint surfaces face in particular directions. These anatomical relationships help create the longitudinal and transverse curvatures.
The skeleton therefore provides more than a collection of individual bones. Its geometry contributes to the mechanical behaviour of the foot. However, the bones alone cannot maintain the arches under load. They need the surrounding connecting and supporting tissues.
Ligaments connect and support the bones
Ligaments are strong connective tissues that connect one bone to another. The foot contains numerous ligaments, including the plantar calcaneonavicular ligament complex, long plantar ligament, short plantar ligament and many smaller ligaments surrounding its joints.
These tissues help maintain anatomical relationships between bones and resist excessive movement in particular directions. Different ligaments become important depending on where forces are applied.
The plantar fascia contributes to arch support
The plantar fascia is a strong fibrous structure extending from the heel towards the toes. It helps resist elongation of the foot under load and contributes to the mechanical behaviour of the longitudinal arches.
Because it can stretch and recoil, it also contributes to the storage and return of elastic energy during movement. It is an important component of foot architecture, but it is not the only structure responsible for supporting the arches.
Muscles provide active support and control
The foot also contains muscles that can influence arch movement. Some of these are intrinsic muscles located entirely within the foot, while others originate in the leg and act upon the foot through their tendons. For example, the abductor hallucis and flexor digitorum brevis are among the intrinsic muscles capable of influencing longitudinal arch deformation.
Research by Kelly and colleagues demonstrated that intrinsic foot muscle activity increases in response to increasing loads and that activation of these muscles can influence arch height and stiffness. This is important because it shows that foot arch behaviour is not determined exclusively by passive structures. Muscles can actively influence how the foot responds to mechanical demands.
5. How Do the Three Arches Work Together When We Walk?
The arches do not act independently. They form an interconnected mechanical system, with movement in one part of the foot influencing another. During walking, the forces passing through the foot constantly change. When the foot contacts the ground, the bones, joints and surrounding soft tissues begin responding to the applied load. As body weight moves over the foot, the longitudinal arches undergo changes in height and length.
The transverse architecture contributes to the foot’s resistance to deformation, while the muscles and connective tissues influence how much movement occurs. Later in the step, as the heel rises and the body moves forward, the foot continues to change shape while transferring forces through the forefoot.
These movements involve complex interactions across multiple joints and tissues. The foot is therefore not simply a spring that compresses and rebounds, nor is it a structure that becomes completely rigid whenever we push off.
Modern biomechanical research increasingly describes the foot as a versatile, adaptable structure whose mechanical response depends upon the task being performed. This explains how the same foot can accommodate the uneven surface of a walking path, support the body during standing and respond to the considerably greater forces generated during running.
6. Should the Arches Be High, Low, Flexible or Stiff?
One of the most important things to understand about the arches is that their visible shape does not tell us everything about their function. People naturally have different foot shapes. Some have relatively high medial longitudinal arches, while others have much lower arches.
But arch height alone does not determine how stiff or mobile a foot will be during movement. A visually high arch does not necessarily mean the entire foot is mechanically rigid. Similarly, a lower arch does not automatically mean that the foot is excessively flexible.
Foot stiffness depends on several interacting factors, including skeletal geometry, joint mobility, ligament properties, plantar fascia behaviour, muscle activity and the direction and magnitude of applied forces.
A foot can also be relatively stiff in one direction while remaining mobile in another. This is an important reason why the three-dimensional structure of the foot deserves more attention than the height of one visible arch.
7. What Modern Research Has Taught Us About the Foot’s Architecture
Our understanding of foot biomechanics continues to develop as researchers gain access to more sophisticated methods of studying movement and internal foot structures. Three broad findings are particularly relevant.
First, skeletal architecture matters.
The arrangement and curvature of the bones influence the mechanical behaviour of the foot. Research on the transverse arch has demonstrated how important three-dimensional geometry can be.
The arrangement and curvature of the bones influence the mechanical behaviour of the foot. Research on the transverse arch has demonstrated how important three-dimensional geometry can be.
Second, the supporting tissues do more than simply hold the arches in place.
Ligaments, the plantar fascia, tendons and muscles influence how forces are transmitted through the foot and how its shape changes under load.
Ligaments, the plantar fascia, tendons and muscles influence how forces are transmitted through the foot and how its shape changes under load.
Third, mobility is essential to foot function.
An influential 2023 review by Behling and colleagues challenged longstanding theories that described the foot primarily as a flexible structure that becomes rigid for propulsion.
Instead, the authors highlighted the importance of ongoing joint mobility and the foot’s ability to adjust its mechanical behaviour during movement. Together, these findings encourage us to think about the foot as an integrated, adaptable anatomical structure rather than simply three arches that must be prevented from flattening.
An influential 2023 review by Behling and colleagues challenged longstanding theories that described the foot primarily as a flexible structure that becomes rigid for propulsion.
Instead, the authors highlighted the importance of ongoing joint mobility and the foot’s ability to adjust its mechanical behaviour during movement. Together, these findings encourage us to think about the foot as an integrated, adaptable anatomical structure rather than simply three arches that must be prevented from flattening.
Conclusion: Three Arches, One Remarkable Structure
The human foot has three principal arches: the medial longitudinal arch, lateral longitudinal arch and transverse arch. Each is created by the anatomical arrangement of the bones and supported by connecting tissues and muscular activity. Although we can describe each arch individually, they do not function independently.
The three arches work together to support weight, distribute mechanical forces and allow the foot to adapt during standing, walking and running
Modern research has strengthened our understanding of the importance of skeletal curvature, joint mobility and active muscular contributions.
Perhaps the most important point is that the arches are not simply structures that must remain raised. They are part of a dynamic three-dimensional system, designed to support loads while permitting movement. Understanding how these three arches normally function provides the foundation for exploring how changes in their structure and mechanics can affect the foot.
Perhaps the most important point is that the arches are not simply structures that must remain raised. They are part of a dynamic three-dimensional system, designed to support loads while permitting movement. Understanding how these three arches normally function provides the foundation for exploring how changes in their structure and mechanics can affect the foot.
This article introduces our educational series on the three arches of the human foot. Subsequent articles will explore the medial longitudinal arch, lateral longitudinal arch and transverse arch individually, including the different structural and mechanical changes that can occur within each.
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Disclaimer: The word "treatment" in this article refers to the care and management of a patient’s health to prevent, cure, or improve a condition. Treatment results vary and do not necessarily indicate a cure. This article is for informational and educational purposes only and does not constitute medical advice.
About the Author
Mark B. Reyneker, BTech (Podiatry), MSc (Palaeontology) is a podiatrist and Founder & Clinical Director of Family Podiatry Centre, with more than 25 years of clinical experience across South Africa, Malaysia and Singapore. His clinical interests include foot and lower-limb pain, gait and biomechanics, sports-related foot conditions, orthotic therapy and footwear.
Alongside his clinical practice, Mark conducts research into human gait and foot biomechanics. His MSc research at the University of the Witwatersrand investigated human propulsion and the structural properties of the metatarsals. He is also the inventor of A Foot Orthotic, an orthotic technology developed through an international patent family.
References
- Venkadesan, M., Yawar, A., Eng, C.M. et al. (2020). Stiffness of the human foot and evolution of the transverse arch. Nature, 579, 97–100.
Avaliable article: https://doi.org/10.1038/s41586-020-2053-y - Kelly, L.A., Cresswell, A.G., Racinais, S., Whiteley, R. and Lichtwark, G. (2014). Intrinsic foot muscles have the capacity to control deformation of the longitudinal arch. Journal of the Royal Society Interface, 11(93), 20131188.
Avaliable article: https://doi.org/10.1098/rsif.2013.1188 - Behling, A.-V., Rainbow, M.J., Welte, L. and Kelly, L.A. (2023). Chasing footprints in time – reframing our understanding of human foot function in the context of current evidence and emerging insights. Biological Reviews, 98(6), 2136–2151.
Avaliable article: https://doi.org/10.1111/brv.12999 - Chauhan, H.M. and Taqi, M. (2025). Anatomy, Bony Pelvis and Lower Limb: Arches of the Foot. StatPearls.
Avaliable article: https://www.ncbi.nlm.nih.gov/books/NBK587361/