What Is the Outside of the Foot Called?

The outside edge of the foot is formally called the lateral border (or lateral side), and the bony chain running along it is known as the lateral column. “Lateral” simply means the side farther from the midline of the body, so the lateral border is the pinky-toe edge that traces from the heel to the fifth toe. Doctors, physical therapists, and podiatrists use these terms constantly, and understanding what they refer to helps make sense of diagnoses, imaging reports, and rehab instructions that would otherwise sound like a foreign language.

The Bones That Form the Lateral Column

The lateral column is a distinct skeletal chain that runs along the outside of the foot. It includes the calcaneus (heel bone), the cuboid, and the fourth and fifth metatarsals, along with the joints that connect them: the calcaneocuboid joint, the cuboido-metatarsal joints, and the intermetatarsal joint between the fourth and fifth metatarsals.¹ Together, these bones form a lower, flatter arch compared to the inside of the foot, and this architecture is a key reason the lateral border acts as a stable platform you push off of during every step.

The foot’s overall structure has been described as a dome that contacts the ground at three points: the heel bone at the back, the head of the first metatarsal on the inside of the forefoot, and the head of the fifth metatarsal on the outside.² If you imagine the foot as a half-arch, the lateral border is the base of that arch, sitting closer to the ground, while the medial (inner) border rises higher. Strong plantar ligaments and the plantar fascia tie the lower edges of these bones together, preventing the arch from collapsing under your body weight.²

The fifth metatarsal deserves special attention because it is the most exposed bone on the lateral border and the one most commonly injured. Its base, the knobby bump you can feel on the outside of your midfoot, serves as an attachment point for tendons and the lateral band of the plantar fascia. The blood supply to portions of the fifth metatarsal base is limited, which matters because poor blood flow in that area increases the risk of slow healing when fractures occur there.³

Tendons and Nerves Along the Lateral Border

Two peroneal tendons run behind the bony bump on the outside of your ankle (the lateral malleolus) and continue along the lateral foot. They are the primary muscles responsible for everting the foot, meaning rolling it outward, and they double as lateral stabilizers of the ankle.⁴ The peroneus brevis inserts directly onto the base of the fifth metatarsal, while the peroneus longus wraps underneath the foot to the inner side. When either tendon becomes inflamed or torn, pain concentrates along the outside of the ankle and foot, and the joint can feel unstable during side-to-side movements.

Peroneal tendon disorders are surprisingly common in people with chronic ankle instability. Repeated ankle sprains stretch or damage the tissue that holds the tendons in their groove behind the ankle, allowing them to slip out of place (subluxation) or develop small tears. If you have lingering pain along the outer ankle after what seemed like a routine sprain, the peroneal tendons are a frequent culprit.

Sensation on the lateral border comes mainly from the sural nerve, which runs down the back of the calf and around the outer ankle before branching across the lateral foot. A study mapping its distribution found that the most common pattern was for the sural nerve to supply the lateral side of the fifth toe, seen in about 60% of specimens, while in roughly a quarter of cases it also covered the lateral two and a half toes.⁵ That variability matters clinically: some people experience numbness or tingling across a wider swath of the outer foot when the sural nerve is irritated, while others feel it only along the pinky toe.

The Lateral Foot in Walking and Sports

During a normal walking stride, your foot typically lands on the outer heel first, rolls inward slightly (pronation), and then pushes off through the big toe. The lateral border serves as the initial contact zone and the stable base from which the rest of the stride unfolds. People with a supinated (high-arched) foot type tend to keep more weight along the lateral border throughout the stride. Research comparing muscle activity in supinated, pronated, and neutral foot types found that the supinated group showed significantly higher activation of the peroneus longus during walking, essentially the muscles along the outer leg were working harder to compensate for the foot’s tendency to stay rolled outward.⁶

Athletic movements put the lateral foot under even more stress. A study measuring forefoot pressures during cutting and acceleration tasks found that crossover cuts, where you plant one foot and push off laterally, produced the highest peak pressure in the lateral forefoot compared to straight-ahead running or side cuts.⁷ Separate research showed that cutting and jumping movements can generate more than double the pressure at the heel compared with running in a straight line.⁸ These forces help explain why athletes in sports that involve frequent direction changes, such as basketball, soccer, and tennis, are particularly vulnerable to lateral foot injuries.

Surface design can reduce that risk. One study tested recreational athletes performing cutting movements on banked surfaces at different angles and found that as the banking angle increased, ankle joint loading in the side-to-side and rotational planes decreased.⁹ That finding is one reason indoor tracks and some court surfaces are designed with gentle banking in the turns.

Common Injuries on the Outside of the Foot

If you search “lateral foot pain” or “pain on outside of foot,” you are in good company. The lateral column absorbs considerable impact and torque, and several conditions concentrate right along the outer border.

Fifth Metatarsal Fractures

Fractures at the base of the fifth metatarsal are among the most frequently seen foot injuries. At least three distinct fracture types occur in this region: tuberosity avulsion fractures, Jones fractures, and proximal diaphyseal stress fractures.¹⁰ The differences are not just academic; the location of the break within the first 1.5 centimeters of the bone determines the likely cause, how fast it heals, and whether surgery is needed.

Tuberosity avulsion fractures, the most common type, happen when a sudden twist pulls a small chip of bone away at the very tip of the base. Research into the exact anatomy suggests the lateral band of the plantar fascia is responsible for most of these avulsions, and because blood supply is relatively good there, many heal with simple immobilization while still allowing the patient to bear weight.¹¹ Surgery becomes necessary when the fracture fragment is displaced more than about 2 mm or involves a large portion of the joint surface.¹²

Jones fractures are a different story. They occur slightly farther along the bone, at the junction between the widened base and the shaft, a zone with particularly poor blood supply. That limited vascularity is the reason Jones fractures are known for prolonged healing times and a higher risk of not healing at all (nonunion).³ Treatment depends on how advanced the injury is and how active the patient plans to be: fresh fractures without displacement can sometimes heal with strict non-weight-bearing immobilization, but delayed or repeat fractures generally require surgical fixation with a screw.¹² Athletes almost always opt for surgery early because the alternative, months in a cast with an uncertain outcome, is impractical for a competitive season.

Cuboid Syndrome

Cuboid syndrome is a less well-known source of lateral midfoot pain. The cuboid sits right in the middle of the lateral column, and the condition is thought to involve a subtle disruption of how the calcaneocuboid joint moves or fits together.¹³ The symptoms feel a lot like a ligament sprain, and there is no definitive diagnostic test, so it often gets overlooked or lumped in with vague “ankle sprain” diagnoses. It is most commonly seen in athletes and dancers who repeatedly load the lateral foot. Manual manipulation by a skilled practitioner is one of the more common treatments, though the evidence base is thin. If you have ongoing pain along the outer midfoot after an ankle injury and imaging comes back clean, cuboid syndrome is worth asking about.

Tailor’s Bunion (Bunionette)

A tailor’s bunion, formally called a bunionette, is a bony prominence on the outer side of the fifth metatarsal head, basically the mirror image of a regular bunion on the big toe side. The name comes from tailors who historically sat cross-legged on hard floors, putting pressure on the outside of their feet. Today the deformity is more often aggravated by narrow or pointed shoes. Symptoms include pain, redness, and swelling right where the outer forefoot rubs against the shoe.¹⁴

Many bunionettes respond to switching to wider, softer shoes and using a mild anti-inflammatory for flare-ups.¹⁵ When conservative measures fail, surgery to realign or shave down the prominent bone is an option. A systematic review of one popular surgical technique found that bunionettes are common forefoot deformities and that the symptoms can be stubbornly resistant to non-surgical care, which is why surgical correction rates remain relatively high.¹⁶

Why “Lateral” and “Medial” Instead of “Inside” and “Outside”

You might wonder why medical professionals do not just say “outside” and “inside.” The reason is that everyday spatial words change meaning depending on which direction you are facing or how the foot is positioned. “Lateral” always means the side away from the body’s center line, and “medial” always means toward it, regardless of how the foot is rotated or angled. That consistency is crucial in surgical planning and imaging reports. If a radiologist writes “lateral column tenderness,” every provider reading the chart knows exactly which side of the foot is being discussed. “Outside” would be ambiguous in certain contexts, such as when the foot is turned inward during examination.

The same convention applies to the sole and top of the foot. The sole is the “plantar” surface, and the top is the “dorsal” surface. You will see these terms constantly in podiatry and orthopedic contexts, so knowing that “lateral” equals the pinky-toe side gives you a reliable translation key for any diagnosis, imaging report, or rehab exercise description that uses formal anatomical language.

How the Lateral Foot Evolved for Upright Walking

The rigid lateral column humans have is not universal among primates. Great apes have a much more flexible lateral foot with a noticeable “midfoot break,” a folding motion through the middle of the foot that helps with gripping branches. Humans lost that flexibility in exchange for a stiff lateral column that acts as a lever during push-off in bipedal walking.

The fossil record suggests this trade-off happened early. A study comparing the shape of the fourth and fifth metatarsal joint surfaces in humans, apes, and several hominin fossils found that the fossils resembled unshod modern humans far more than apes, implying a stable lateral column was already present.¹⁷ A separate analysis of one of the earliest complete fifth metatarsals in the hominin fossil record reached a similar conclusion, noting that its joint surfaces and internal head torsion were very human-like, suggesting the presence of both a lateral longitudinal arch and a transverse arch.¹⁸ The researchers proposed that increased stability at the calcaneocuboid joint, right in the heart of the lateral column, may have been one of the earliest skeletal adaptations for habitual upright walking.

That evolutionary context helps explain why the lateral column is simultaneously so sturdy and so injury-prone. It was shaped for the repetitive, moderate forces of barefoot walking and running over natural terrain. The sudden, high-magnitude loads of modern athletic movements on hard artificial surfaces push it into territory it was not originally designed for, which is part of the reason fifth metatarsal fractures remain one of the most common athletic foot injuries.

When Children’s Lateral Foot Bones Develop

If you are a parent whose child has been told they have lateral foot pain, it helps to know that the bones on the outside of the foot do not all harden on the same schedule. The foot’s bones begin as cartilage and gradually ossify (turn into solid bone) over childhood and adolescence. Research mapping ossification timelines found that while the cuboid, navicular, cuneiforms, and metatarsals did not differ significantly between boys and girls, other tarsal bones showed a later and slower ossification rate in boys.¹⁹

The practical takeaway is that growing feet have growth plates and partially ossified bones that are vulnerable to types of injuries adults do not typically get. A child or adolescent with pain at the base of the fifth metatarsal might have an apophysitis (irritation of a growth plate) rather than a fracture. Imaging can look confusing in young patients because the normal growth centers mimic fracture lines on X-ray. Pediatric foot pain on the outside of the foot should be evaluated with the child’s skeletal maturity in mind, and providers familiar with developmental anatomy are better equipped to distinguish a normal growth variant from an injury that needs treatment.