The tarsal bones are the seven irregularly shaped bones that make up the back half of your foot, sitting between your leg bones above and your long metatarsal bones in front. They include the talus, calcaneus, navicular, cuboid, and three cuneiforms. Together they bear your full body weight, form the arches of your foot, and allow the complex motions that let you walk, run, jump, and balance on uneven ground. These bones are involved in a surprisingly wide range of injuries, conditions, and evolutionary stories that go well beyond their quiet reputation as the “ankle bones.”
The Seven Bones and How They Work Together
Your foot has 26 bones in total, and the tarsal group accounts for seven of them. The largest is the calcaneus, or heel bone, which absorbs the initial shock every time your foot hits the ground. Sitting on top of it is the talus, which forms the main hinge of your ankle joint by connecting the foot to the tibia and fibula of the lower leg. In front of the talus is the navicular, a boat-shaped bone on the inner side of the foot that serves as the keystone of the medial arch. On the outer side, the cuboid sits in front of the calcaneus and provides the lateral column of the foot. Finally, three small cuneiform bones (medial, intermediate, and lateral) line up in a row between the navicular and the bases of the first three metatarsals.
These bones don’t just stack passively. They form a set of interlocking joints that allow the foot to shift between being a flexible shock absorber and a rigid lever. When your heel first strikes the ground, the subtalar joint (between the talus and calcaneus) and the midtarsal joints (talonavicular and calcaneocuboid) allow your foot to flatten and spread, cushioning the impact. As you push off, those same joints stiffen, turning the foot into a firm platform for propulsion.
Powering Your Step
The interplay between tarsal bones during a single walking step is more dynamic than most people realize. The midtarsal joint doesn’t simply “lock” into a rigid position during push-off, as older textbook descriptions suggested. Research tracking individual bone movements during walking has shown that the midtarsal joint continuously moves toward an extreme supinated position in the terminal stance phase, working alongside activated muscles to stiffen the foot for effective force transfer as you push off the ground.
1PubMed. Skeletal kinematics of the midtarsal joint during walking: Midtarsal joint locking revisitedThe arches of the foot depend heavily on tarsal bone architecture. The transverse arch, which runs across the midfoot from side to side, has a predominant role in midfoot stiffness. That stiffness lets your foot store elastic energy when your heel strikes the ground, then release it during push-off, making walking and running more energy-efficient.
2PubMed Central. Instructional Lecture: Foot & AnkleAn Evolutionary Perspective
The shape of tarsal bones tells a story about how our ancestors moved. When researchers study fossil hominins, the talus and calcaneus are among the most informative bones for understanding the shift from tree-dwelling to upright walking. Analysis of the roughly 3.3-million-year-old Stw 573 (“Little Foot”) skeleton found that this early hominin had a very ape-like talus, a navicular that was intermediate between apes and modern humans, and a human-like medial cuneiform. That combination suggests a foot already adapted for walking without an opposable big toe, but still retaining some features associated with climbing.
3PubMed Central. Fossils, feet and the evolution of human bipedal locomotionIn primates more broadly, the calcaneus reveals a lot about locomotion. A longer calcaneus correlates with leaping ability, because the elongated heel bone gives the Achilles tendon a longer lever arm for explosive push-off. Early increases in calcaneal elongation during primate evolution may have been tied to the development of grasping with the big toe, or a combination of grasping and specialized leaping behaviors. Later increases are thought to reflect adaptations for acrobatic leaping, a behavior central to early primate life in the trees.
4PubMed Central. Evolution and allometry of calcaneal elongation in living and extinct primatesTarsal Bones in Birds
If you want to see just how radically tarsal bones can be reshaped by evolution, look at birds. In the dinosaur-to-bird transition, the separate distal tarsal bones fused together and then fused to the tops of the metatarsals, creating a single composite structure called the tarsometatarsus. This bone is essentially a fusion of ankle and foot elements into one unit, and it is the most highly connected bone in the avian foot, meaning nearly every digit, muscle, and tendon in the foot depends on it.
5PubMed Central. Evolution of avian foot morphology through anatomical network analysisDevelopmental studies have traced how this happened. In bird embryos, three separate distal tarsal cartilages fuse into a single cartilage mass, and then a single ossification center expands into a plate-like unit covering the tops of the metatarsals. One of the original ossification centers was effectively lost during evolution, replaced by expansion of its neighbor. The result is a remarkably integrated structure that gives birds their characteristic leg anatomy, with what looks like a backward-bending “knee” actually being the ankle (the intertarsal joint).
6PubMed. Developmental evolution of the distal ankle in the dinosaur-bird transitionTalus Fractures
The talus is one of the most injury-prone tarsal bones, and fractures of the talar neck are particularly serious. A systematic review of talar neck fractures found that across all fracture types, about a quarter of patients developed avascular necrosis, a condition where the bone tissue dies due to disrupted blood supply. The risk climbed steeply with severity: avascular necrosis occurred in none of the mildest fractures but in over half of the most severe ones. Osteoarthritis was even more common, developing in roughly half of all talar neck fracture patients overall, and in nearly three-quarters of those with the worst injuries.
7PubMed. Complications of Talar Neck Fractures by Hawkins Classification: A Systematic ReviewThe talus is vulnerable to blood supply problems because it is largely covered in cartilage, with limited surface area for blood vessels to enter. When a fracture disrupts those vessels, the bone can struggle to heal. Although complications like osteonecrosis and post-traumatic arthritis still occur at high rates even with modern surgical techniques, treatment decisions are generally guided by patient symptoms rather than by the imaging findings alone.
8PubMed Central. Current Concepts in Talar Neck Fracture ManagementNavicular Stress Fractures
While talus fractures tend to result from acute trauma like falls or car crashes, the navicular is more prone to overuse injuries. Navicular stress fractures are considered high-risk injuries, most commonly affecting athletes, military recruits, and others engaged in repetitive weight-bearing activities. The navicular functions as the keystone of the medial arch, meaning it absorbs considerable compressive force with every step. Compounding the problem, its central zone has a relatively poor blood supply, which makes healing slow and unreliable.
9PubMed Central. Navicular Stress Fractures: A Narrative Review of Pathoanatomy, Diagnostic Pitfalls, and ManagementRisk factors go beyond just overtraining. Female sex, a history of previous foot injury, dietary insufficiencies, and relative energy deficiency in sport all raise the likelihood. These fractures are notorious for being missed on initial X-rays, which can delay treatment and lead to chronic problems. When caught early, a period of non-weight-bearing immobilization often allows healing, but delayed or displaced fractures sometimes require surgery.
10PubMed Central. Review of Current Management of Navicular Stress Fractures in AthletesLisfranc Injuries
The junction between the tarsal bones and the metatarsals is held together by a web of ligaments, and the most important of these is the Lisfranc ligament complex. Injuries here can range from a subtle ligament sprain to a full dislocation of the midfoot, and they are frequently underdiagnosed because the initial swelling and pain can look like a simple sprain. The hallmark signs are swelling across the midfoot and pain with instability.
11PubMed Central. Lisfranc complex injuries management and treatment: current knowledgeSubtle Lisfranc injuries, where the bones haven’t obviously shifted on X-ray, are the trickiest to diagnose. MRI research has found that the strongest predictor of instability is disruption of a specific ligament on the bottom of the foot running between the first cuneiform and the bases of the second and third metatarsals. When that plantar ligament was torn, instability was present about 94% of the time.
12Journal of Bone and Joint Surgery. Prediction of Midfoot Instability in the Subtle Lisfranc Injury: Comparison of Magnetic Resonance Imaging with Intraoperative FindingsTarsal Coalition
Sometimes two tarsal bones that should be separate end up partly or fully joined, a condition known as tarsal coalition. This is a developmental abnormality present from birth, though symptoms often don’t appear until late childhood or adolescence, when the abnormal connection begins to ossify and stiffen. The most common type involves the talus and calcaneus (talocalcaneal coalition), and it frequently leads to flatfoot deformity in children. The limited motion at the fused joint forces the surrounding joints to compensate, which can cause pain and fatigue during activity. Treatment ranges from supportive shoe inserts to surgery, depending on severity and how much the coalition restricts daily life.
13PubMed Central. Talocalcaneal coalition combined with flatfoot in children: diagnosis and treatment: a reviewAccessory Tarsal Bones
Not everyone has exactly seven tarsal bones. Small extra bones, called accessory ossicles, are common normal variants. The os trigonum sits behind the talus, the accessory navicular is an extra piece attached to the navicular on the inner side of the foot, and the os peroneum is a small bone embedded in a tendon on the outer side. Most people with these extras never know they have them. But they can become clinically relevant when they cause tendon irritation or develop their own pathology. In a study of patients who had an os trigonum on MRI, about 19% also had an accessory navicular, and roughly 5% had an os peroneum as well. The most common problems were bone marrow edema in the extra bone itself and increased fluid around the related tendon sheath.
14PubMed. The coexistence of os trigonum, accessory navicular bone and os peroneum and associated tendon and bone pathologiesTarsal Tunnel Syndrome
The tarsal tunnel is a narrow passageway on the inner side of the ankle, roofed by a band of tissue called the flexor retinaculum and floored by the talus and calcaneus. The posterior tibial nerve, artery, and several tendons all pass through this tight space. When the nerve gets compressed, the result is tarsal tunnel syndrome: pain, numbness, tingling, and sometimes weakness along the sole of the foot.
15PubMed Central. Tarsal Tunnel Syndrome – A Comprehensive ReviewAnything that physically reduces the volume of the tunnel can trigger symptoms. Ganglion cysts, varicose veins, bone spurs, or even post-fracture swelling around the tarsal bones are all potential culprits. The condition is sometimes compared to carpal tunnel syndrome in the wrist, and the analogy is fair: both involve nerve compression in a bony-ligamentous tunnel. Diagnosis can be tricky because the symptoms overlap with plantar fasciitis and other causes of foot pain, but nerve conduction studies and MRI usually clarify the picture.
16PubMed Central. An Update on Posterior Tarsal Tunnel SyndromeKöhler Disease in Children
While navicular stress fractures are primarily an adult and adolescent athlete problem, younger children can develop their own navicular condition. Köhler disease is avascular necrosis of the navicular in children, typically appearing between ages 2 and 10, with boys affected more often than girls. A child will present with pain and swelling on the inner side of the midfoot, and X-rays show the navicular looking abnormally dense, flattened, or fragmented. The good news is that long-term outcomes are favorable regardless of treatment approach. A short period in a walking cast often shortens the duration of symptoms, but even without that, the bone typically remodels and recovers on its own.
17PubMed. Köhler Disease: Avascular Necrosis in the ChildCharcot Foot and Diabetes
Diabetes can affect the tarsal bones in a particularly destructive way through a condition called Charcot foot. Now understood as an inflammatory syndrome, Charcot foot involves progressive bone and joint disorganization driven by underlying neuropathy, minor trauma, and disrupted bone metabolism. When someone has severely reduced sensation in their feet from diabetic nerve damage, they may continue walking on an injured foot without realizing it, and the repeated unrecognized trauma causes bones to fracture, fragment, and collapse. The midfoot tarsal bones are a common site of destruction, and the resulting deformity can lead to a “rocker-bottom” foot shape that creates dangerous pressure points and ulcers.
Advanced Imaging of Tarsal Joints
Standard X-rays capture the tarsal bones reasonably well for obvious fractures, but they have real limitations when it comes to measuring joint alignment and detecting subtle problems. Conventional X-rays and even standard CT scans are affected by how the foot is positioned during the scan, which introduces rotational and projection bias. Weight-bearing CT, a relatively newer technology that scans the foot while you stand on it, eliminates these errors and provides the true measurements of tarsal joint alignment.
18PubMed Central. Instructional Lecture: Foot & AnkleWeight-bearing CT has proven especially useful for mapping how joint surfaces relate to each other under real load. In patients with cavovarus foot deformity (a condition where the foot is excessively arched and turned inward), distance mapping revealed that tarsal joint spacing shifts in specific patterns: increased distances at the sinus tarsi, the outer side of the talonavicular joint, and the naviculocuneiform and tarsometatarsal joints compared to normal feet. These measurements help surgeons plan corrections more precisely.
19PubMed. Distance mapping of the foot and ankle joints using weightbearing CT: The cavovarus configurationWhat Happens When You Fuse a Tarsal Joint
When arthritis or injury makes a tarsal joint too painful to tolerate, one surgical option is arthrodesis, or joint fusion. Fusing the ankle joint (between the tibia and talus) is a well-established procedure, but it comes with a trade-off that plays out in the surrounding tarsal joints. Cadaver research has shown that after ankle fusion, pressure increases substantially in the talonavicular and calcaneocuboid joints, especially during the push-off phase of walking. These pressure increases are consistent with the clinical observation that patients who undergo ankle fusion often develop arthritis in those neighboring tarsal joints years later.
20PubMed. Effect of tibiotalar joint arthrodesis on adjacent tarsal joint pressure in a cadaver modelThis cascading effect is a recurring theme in tarsal bone medicine. Because the seven bones and their joints function as an integrated system, altering one joint inevitably shifts stress to its neighbors. It is one reason surgeons increasingly consider total ankle replacement over fusion in appropriate candidates, and why any intervention in the midfoot or hindfoot requires thinking several joints downstream.
How Footwear Reshapes Tarsal Bones Over Time
Tarsal bones aren’t static structures. They physically remodel in response to the mechanical loads placed on them over a lifetime, and cultural practices, especially footwear, leave measurable traces. A study comparing calcaneal and talar measurements between Medieval and Post-Medieval London populations found quantifiable differences in bone dimensions that corresponded with the shift in footwear styles between those periods. The magnitude of the changes varied by sex, suggesting that differences in the types of shoes worn by men and women created distinct mechanical environments that shaped their tarsal bones differently.
21HOMO. Tarsal metric trends over the Medieval-Post-Medieval transition in LondonSeparate research on early Holocene hunter-gatherer populations found no significant sex-based differences in the dimensions of weight-bearing or shock-absorbing tarsal bones when body-size corrections were applied. The contrast with the London study is revealing: in a barefoot or minimally shod population, male and female tarsals show similar proportional shapes, but once culturally differentiated footwear enters the picture, sex-based differences in tarsal dimensions emerge. Your tarsal bones, in other words, are a physical record of how you’ve used your feet across your life.
22PubMed Central. Early Holocene morphological variation in hunter-gatherer hands and feet