Ankle Ligaments: A Plain Guide to Each Band and What It Does

Ankle ligaments are short, tough bands that tie the bones of the lower leg to the foot. There are more of them than most people expect, but they sort into three groups. Three run down the outer side of the ankle. One broad, fan shaped ligament covers the inner side. A small group sits just above the joint and binds the two lower leg bones to each other. Each group has a job, and each gets hurt in its own way. I teach the Feldenkrais Method®, so I am also interested in what these bands tell your brain, and what happens to that message after a sprain.

Ankle ligaments begin with three bones

The shin bone, the tibia, carries most of your weight down the leg. Beside it runs the fibula, a thinner bone on the outer side. At the bottom, each one ends in a bump you can feel. The inner ankle bone belongs to the tibia, the outer one to the fibula. Between those two bumps sits the talus. The talus is a squat, saddle shaped bone with no muscles attached to it at all. Only the shape of the socket and the ligaments hold it in place. Beneath the talus lies the heel bone.

So the ankle is really two joints. The upper one, between the lower leg bones and the talus, is a hinge. It points the foot down and pulls it up. The lower one, between the talus and the heel bone, tilts the foot inward and outward. Ligaments cross both, and a few cross the pair.

The three outer ligaments: ATFL, CFL and PTFL

Three ligaments fan out from the outer ankle bone, and their long names simply describe where they go. The anterior talofibular ligament, the ATFL, runs forward from the front edge of the outer ankle bone to the talus. It is the thinnest of the three, little more than a thickening of the joint capsule. It tightens when the foot points down, and it is the first to tear in most sprains.

The calcaneofibular ligament, the CFL, drops from the tip of the outer ankle bone down and slightly back to the outer side of the heel bone. It is a rounder cord, and it crosses both joints. It stops the foot tipping too far inward when the foot is flat or pulled up. In a harder sprain it tears along with the ATFL.

The posterior talofibular ligament, the PTFL, runs from the back of the outer ankle bone to the back of the talus. It is thick, short and nearly horizontal, and it is the strongest of the three. It rarely tears unless the ankle has come right out of joint.

The deltoid ligament on the inner side

The inner side has one ligament rather than three, and it is built very differently. The deltoid ligament is named for its shape: a wide triangle, like the Greek letter delta. Its point sits at the inner ankle bone and its base spreads across the foot. It has a surface layer and a deep layer. Its fibres reach the talus, the heel bone and the navicular, a boat shaped bone on the inner side of the midfoot.

The deltoid is much thicker and stronger than the outer three together. It stops the foot rolling outward and keeps the talus from sliding sideways. Because it is so strong, it is sprained far less often. When it is, the force was often big enough to break the fibula as well, so an inner side sprain tends to be checked with an X ray.

The high ankle ligaments, or syndesmosis

Just above the joint, the two lower leg bones are lashed together by a set of ligaments called the syndesmosis. A syndesmosis is simply a joint where bones are held by fibrous tissue rather than meeting on a smooth sliding surface. One band runs across the front of the two bones, one across the back, and a thick wad of fibres fills the gap between them. Those fibres continue up the leg as a sheet between the tibia and fibula.

Their job is to keep the socket around the talus the right width. When the foot pulls up, the wide front of the talus pushes the two bones slightly apart, and these ligaments spring them back. A sprain here is called a high ankle sprain. It usually happens when the foot is planted and the body turns over it, twisting the foot outward. Skiers and people in contact sports see it most.

Why the outer ankle ligaments are sprained most

Ask any emergency department which ankle ligaments they see torn, and the answer is the outer three, and above all the ATFL. There are three plain reasons.

First, the bones allow it. The outer ankle bone reaches further down than the inner one. So the foot can tip inward a long way before bone meets bone, but it is blocked quickly when it tips outward. Second, the ligaments are unequal. The deltoid on the inside is a thick fan, while the ATFL on the outside is a thin strip. Third, the way we fall. Most sprains happen with the foot pointed down and rolling in: landing from a step or a jump, or catching the edge of a kerb. In that position the narrow back of the talus sits in the socket, so the joint is at its loosest. The ATFL is pulled tight and takes the load alone. The muscles on the outer side of the shin, the peroneals, can pull the foot back if they react in time. Often they do not.

How a sprained ankle feels

Sprains are graded by how much of the band gave way. A grade one sprain stretches it and tears a few fibres. Grade two tears part of it. Grade three tears it right through. In an outer sprain the pain sits just in front of and below the outer ankle bone. Swelling arrives within hours. Bruising often shows a day or two later, and gravity draws it down toward the heel and the toes, which looks alarming but is usual. Some people feel or hear a pop. Walking hurts at first, and the ankle may feel wobbly or give way.

A high ankle sprain feels different. The pain sits higher, between the two lower leg bones, and swelling may be modest. Pushing off to walk hurts, and turning the foot outward hurts more. It also heals more slowly, because the two bones tug at the mending fibres with every step. An inner side sprain hurts on the inside of the ankle after the foot rolled outward, and needs a doctor's look for the reasons above.

The NHS puts the timeline plainly. Most sprains feel better after about 2 weeks, while a severe one can take months to get back to normal (NHS, 2024). Our guide to a rolled ankle walks through those first hours and weeks in detail.

Ankle ligaments and your sense of balance

Ligaments are not just rope. They are threaded with tiny sensors that report how far the band is stretched and how fast. Together with sensors in the muscles and skin, they give you proprioception: the sense of where your foot is and which way it is tilting, without looking. Stand on one leg, close your eyes, and feel the small adjustments under your foot. That is the ankle ligaments talking.

A sprain tears some of those sensors along with the fibres. For weeks or months afterward, the report from that ankle is blurry. The brain responds the way it does to any unclear signal. It braces the muscles around the joint and reacts a beat late on uneven ground. That late reaction is how many second sprains happen. It is also why some ankles stay stiff or unreliable long after the pain has gone. Our guide to stiffness in the ankle after a sprain is written for that stage.

The picture can be sharpened again. Balance practice means standing on the recovering leg and letting your weight drift around the sole. It is among the best supported ways to lower the chance of a second sprain. Our page of proprioception exercises for the ankle is a gentle version. The Feldypedia article on proprioception and why it fades with age explains the wider idea.

Where a Feldenkrais® lesson comes in

Balance drills work on the ankle itself. In my teaching I am just as interested in the rest of the person standing on it. After a sprain, the hip and the lower back often take over the ankle's job without anyone deciding it. The foot gets placed carefully, the knee stays a little bent, and the whole leg is used less. An Awareness Through Movement® lesson works on that habit through slow, small movements. You might lie on your back and tip one foot gently so the sole faces inward, then outward, following the movement up through the knee into the hip. Or you stand and let your weight travel around the sole so slowly that each ligament gets a turn to report. Nothing is pushed, and comfort decides the size of every movement.

What tends to change is trust. Many people describe the moment the injured foot stops feeling foreign and simply feels like a foot again. The Feldy online movement program offers lessons like this as short daily audio sessions, with a free 7 day trial and no credit card needed. The page for recovery after injury shows how they are shaped for a healing joint.

Alongside clinical care and other methods

Knowing the ligaments does not replace having a torn one examined. If a physiotherapist, sports doctor or osteopath is guiding your recovery, this kind of awareness work sits beside their plan and never in place of it. Strength work for the outer shin muscles, a brace for sport in the early months, and a graded return to running are their territory. Yoga, Pilates and tai chi also ask a lot of the ankle, each through its own route. Yoga works through held standing shapes, Pilates through precise repeated control, and tai chi through slow weight shifts. Feldenkrais® works through tiny, slow, comfortable movements and attention, which suits a joint that is still touchy.

When an ankle injury needs a doctor

A few signs mean the question is a fracture rather than a sprain, and that question needs an answer today. Get the ankle checked the same day if you cannot put weight on the foot or take a few steps. The same applies if you heard a crack at the moment of injury, or if the ankle or foot has changed shape or sits at an odd angle. Numbness, tingling or pins and needles in the foot belong on the list, and so does skin that turns blue, grey or cold. Swelling that balloons fast and hard is another reason. Pain on the inner side after the foot rolled outward, or pain above the joint between the lower leg bones, deserves a professional look too. Those injuries are easier to miss and slower to heal.

Find where to start

You now know which band sits where, and why the outer side takes most of the knocks. The next question is what kind of practice suits the way you like to learn.

Unsure what kind of practice would suit your ankles? Take the 60-second Movement Match quiz: your three answers sort Feldenkrais, Pilates, yoga and others down to one.

Common Questions about ankle ligaments (FAQ)

Is it safe to move a sprained ankle at home while the ligaments heal?

For a mild or moderate sprain, yes, provided every movement stays small, slow and comfortable. Gentle early motion tends to settle a sprain sooner than long stillness. Wait for a clinician's go ahead if you cannot bear weight, if the ankle has changed shape, or if part of the foot is numb. The same applies when the pain is on the inner side or above the joint. People with brittle bones, with numb feet from diabetes, or with a recent fracture in the same leg should let a clinician decide first.

How often should I practise balance for my ankle ligaments?

Two or three minutes on most days does more for the ankle than a single long session at the weekend. Standing on the recovering leg while you wait for the kettle is enough to start. Once that feels easy, add small weight shifts, then a cushion under the foot. Keep every version comfortable, and stop before it turns into a struggle.

How long do ankle ligaments take to heal after a sprain?

Ligaments heal slowly, partly because their blood supply is thin. A mild sprain usually feels much better within two weeks, and a moderate one within about six. A complete tear can take three months or more to feel strong, and high ankle sprains sit at the slow end. Feeling sure of the ankle on rough ground often comes last, and it comes sooner with balance practice.

Do ankle ligaments heal on their own, or do they stay loose?

Most do heal on their own. Scar tissue fills the tear and then matures over several months. A fully torn outer ligament may heal a little longer than it was, which leaves some ankles looser than before. What matters more for day to day steadiness is how well the muscles and the sense of position around the joint are working. Surgery is kept for the few whose ankle keeps giving way despite good rehabilitation.

How is a high ankle sprain different from a normal ankle sprain?

A normal sprain is an injury to the outer ligaments, usually from the foot rolling inward, with pain and swelling below the outer ankle bone. A high ankle sprain injures the ligaments that bind the two lower leg bones together, usually from the foot being forced outward while planted. The pain sits above the joint, swelling can be mild, and pushing off hurts more than standing still. It takes longer to heal and is more often treated with a boot, so it deserves a clinician's assessment.

What is the best exercise for ankle ligaments after a sprain?

Single leg balance is the one most people should not skip, because it retrains the sense of position the sprain disturbed. Start beside a counter, then try it with eyes closed, then on a soft surface. Slow ankle circles and gentle foot tilting keep the joint moving in the first weeks. A physiotherapist can add strength work for the muscles on the outer shin. Awareness lessons sit alongside all of that and ask the whole leg to share the standing again.

What should I avoid while ankle ligaments are healing?

In the first two days, avoid heat, alcohol, rubbing the swollen area and anything that makes it throb, all of which can make it puff up more. For the first weeks, avoid uneven ground, running and sports that involve turning until the ankle feels steady on one leg. The other extreme is unhelpful too: a mild sprain does not need weeks of boot or sofa. A joint that sits still for weeks loses both its range and its sense of position. Let comfort decide how far and how fast.

When does an ankle sprain need a doctor rather than home care?

The same day if you cannot take a few steps, if you heard a crack, or if the ankle has changed shape. Numbness, tingling, or skin that goes blue, grey or cold also mean the same day. Within a few days if the pain is on the inner side or above the joint. Those sprains often come with a fracture, or are slow to settle. And at any point if pain, swelling or giving way is not improving after two to three weeks of sensible care.