Foot and Ankle Anatomy: What Every Bone and Ligament Actually Does
Your foot contains 26 bones, over 30 joints and more than 100 ligaments and tendons working together. The ankle ligaments hold your ankle stable, the arches absorb shock, and the bones transfer your entire body weight to the ground. When any part is misaligned, pain can appear in the foot, knee, hip or back.
Key takeaways
- Each foot has 26 bones split into three regions: hindfoot, midfoot and forefoot.
- Ankle ligaments on the outer and inner side prevent the joint from rolling.
- The medial arch is your main shock absorber and is supported by the plantar fascia.
- Misalignment in the foot can cause compensatory pain further up the body.
- Standing, weight-bearing imaging shows how these structures behave under real load.
How many bones are in the foot and what do they do?
Each foot has 26 bones, making both feet together nearly a quarter of every bone in your body. They are grouped into three regions that work as a team.
Hindfoot
The calcaneus (heel bone) is the largest bone in the foot and absorbs the initial impact every time your foot hits the ground. Sitting on top of it is the talus, which forms the ankle joint with your lower leg bones. Together they create the subtalar joint, which lets your foot tilt inward and outward.
Midfoot
Five bones, including the navicular, cuboid and three cuneiforms, bridge the gap between the heel and the forefoot. They lock together to form a rigid lever when you push off during walking. The midfoot is where the arch gets its shape.
Forefoot
Five metatarsals fan out toward your toes, and 14 smaller phalanges make up the toes themselves. The metatarsal heads bear a large share of your weight during the push-off phase of each step.
What are the main ankle ligaments and why do they matter?
Ankle ligaments are tough bands of tissue that connect bone to bone, holding the joint together while still allowing movement. The ankle has ligaments on both sides, and each group resists a different direction of roll or twist.
Three ligaments, including the ATFL (anterior talofibular ligament), prevent the ankle from rolling outward. The ATFL is the most commonly sprained ligament in the body.
A thick, fan-shaped ligament on the inside of the ankle. It resists the foot rolling inward and is stronger than the outer ligaments, so inner ankle sprains are less common.
These connect the two lower leg bones (tibia and fibula) just above the ankle joint. A "high ankle sprain" injures this group and typically takes longer to heal.
When ankle ligaments are stretched or torn, the joint can become unstable. Over time, repeated instability changes the way weight is distributed across the foot, which can lead to problems such as peroneal tendonitis on the outer side of the ankle.
What does the arch of the foot actually do?
The arch of the foot acts as a spring, absorbing shock when you land and storing energy to help push you forward. You actually have three arches, but the medial (inner) arch is the most important for weight bearing.
The plantar fascia, a thick band of connective tissue running along the sole, supports the medial arch like a bowstring. If the arch flattens too much (overpronation), the plantar fascia is overstretched, and your ankle, knee and hip have to compensate. If you are experiencing ongoing foot pain linked to flat feet or rolling ankles, learning about orthotics and overpronation can help you understand your options.
The Achilles tendon connects your calf muscles to the calcaneus and plays a vital role in lifting the heel during each step. When the arch collapses, the Achilles can be loaded unevenly, contributing to heel and lower-leg discomfort.
How does foot alignment affect the rest of your body?
Your body is a connected chain from feet to head. When alignment is off at the foundation, every joint above has to adjust. A foot that rolls inward can rotate the shin, twist the knee, tilt the pelvis and curve the spine. This is why foot and ankle anatomy matters well beyond the ankle itself.
Inward rolling can stress the knee and hip over time.
Poor shock absorption sends more force into the ankle and shin.
Loose ligaments alter your gait, which the body compensates for higher up.
A thorough gait analysis can reveal how these compensations play out during walking. But understanding the static alignment of the bones and joints while you stand is the essential first step.
Why is a standing scan better for checking foot and ankle alignment?
A standing scan captures your bones and joints under your full body weight, exactly as they behave in daily life. When you lie down for a conventional X-ray, CT or MRI, gravity is removed, muscles relax, and alignment problems can disappear from the image.
Weight-bearing EOS imaging shows your foot and ankle under real load. The arch height, the spacing between joints, and the alignment of the entire lower limb are captured as they truly are. With ScanAlign, weight-bearing standing imaging, the scan uses about 90% less radiation than a standard X-ray, around ten times less.
Lying-down imaging removes the effect of body weight. A collapsed arch may look normal. A subtle tilt in the ankle or knee may vanish. The result can be a scan that looks reassuringly normal while your symptoms continue.
When is MRI the better choice? EOS shows bones, joints and alignment. For soft-tissue injuries such as torn ligaments, cartilage damage or nerve problems, MRI is usually the better tool. Your clinician can advise which scan you need.
Want to see how your foot and ankle alignment looks under real weight? A free video consultation can help you decide if a standing scan is right for you.
Book a free video consultationWhat signs suggest a foot or ankle alignment problem?
Many people live with subtle alignment issues for years without realising the cause. The following signs may point to a structural problem worth investigating.
Soles that wear down more on one side suggest your weight is not evenly distributed.
Repeated rolls or giving way may indicate ligament laxity or bony misalignment.
Foot misalignment can push compensation upward, so the painful area may not be the source.
Both extremes change how forces travel through the foot and up the leg.
If you notice any of these alongside numbness, weakness, or loss of bladder or bowel control, seek urgent medical attention from your GP, 111 or A&E. These symptoms need immediate assessment.
Frequently asked questions about foot and ankle anatomy
Each foot has 26 bones, divided into the hindfoot (calcaneus and talus), midfoot (navicular, cuboid and three cuneiforms) and forefoot (five metatarsals and 14 phalanges). Both feet together contain 52 bones.
The ATFL (anterior talofibular ligament) is the most commonly injured ankle ligament. It sits on the outer side and prevents the foot from sliding forward and rolling inward. A sprain here is what most people mean by a "twisted ankle".
The deltoid ligament is a strong, fan-shaped structure on the inner side of the ankle. It resists the foot from rolling outward (eversion) and provides medial stability. It is less often sprained than the outer ligaments because of its thickness.
The plantar fascia is a thick band of tissue running along the sole from the heel to the base of the toes. It supports the medial arch and acts like a spring during walking. When it is overstretched or inflamed, it causes plantar fasciitis, one of the most common causes of heel pain.
Yes. When the arch collapses, the foot rolls inward, which rotates the shin and can alter alignment at the knee, hip and even the lower back. Pain felt higher up can sometimes be traced back to a foot alignment issue.
The subtalar joint sits between the talus and the calcaneus, just below the ankle joint. It allows your foot to tilt inward (inversion) and outward (eversion), which is essential for walking on uneven ground.
When you lie down, your body weight is removed from the foot. The arch may spring back to a normal shape, and joint spacing can look fine. A standing, weight-bearing scan captures the bones and joints under real load, revealing alignment problems that only appear when you are upright.
EOS uses about 90% less radiation than a standard X-ray, around ten times less. It captures a full standing image in a single pass, so repeat exposures are rarely needed.
No. ScanAlign accepts self-referrals. You can book a weight-bearing foot scan directly, starting with a free video consultation to check whether a standing scan suits your situation.
ScanAlign is a private self-pay clinic. For up-to-date pricing and what is included, visit the FAQs and cost page.
See how your feet and ankles align under real weight
A free video consultation helps you decide if a standing scan is the right next step for your symptoms.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- Brockett, C.L. & Chapman, G.J. (2016). Biomechanics of the ankle. Orthopaedics and Trauma, 30(3), 232-238.
- NHS. Sprains and strains. nhs.uk. Available at: https://www.nhs.uk/conditions/sprains-and-strains/
- Golano, P. et al. (2010). Anatomy of the ankle ligaments: a pictorial essay. European Radiology, 20(3), 607-620.
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.