The ankle and foot: 26 bones, three arches and how to keep them strong

26 bones and 33 joints

7 tarsal bones, 5 metatarsals and 14 toe bones, plus 2 sesamoids under the big toe that the usual count leaves out.

Sources 1, 2, 3

Three joints do most of the work

The ankle tips the foot up and down, the subtalar joint tilts it in and out, and the midfoot joints let it flex, then stiffen for push-off.

Sources 4, 1, 2

Three arches and a windlass

When your big toe bends at push-off, the plantar fascia along the sole tightens and lifts the arch.

Sources 5, 6, 7

Feet get stronger with use

In one trial, walking in minimalist shoes strengthened foot muscles as much as foot exercises over 8 weeks.

Source 8

Change shoes slowly

Runners who switched to minimalist shoes had more injuries, and minimalist shoes haven't been shown to prevent injuries.

Sources 9, 10, 11

Balance training prevents sprains

It cut ankle sprains in sport by about a third, and repeat sprains after a first one from 33% to 22%.

Sources 12, 13

The bones

26 in the usual count:

• Hindfoot: the talus, which carries your weight from the leg to the foot and has no muscles attached, and the calcaneus (heel bone).
• Midfoot: the navicular, the cuboid and three cuneiforms.
• Forefoot: 5 metatarsals and 14 phalanges, two in the big toe and three in each of the others.
• Sesamoids: two small bones under the ball of the big toe, left out of the 26, which is why some sources say 28. Extra (accessory) bones are common too: one behind the talus, the os trigonum, is found in 1% to 25% of people.

Sources 1, 14, 3

The joints

Each foot has 33 joints. These matter most:

• Ankle (talocrural) joint: the talus sits in a socket formed by the two shin bones and works as a hinge, tipping the foot up (dorsiflexion) and down (plantarflexion). The talus is wider at the front, so the ankle is most stable with the foot pulled up.
• Subtalar joint: the talus sits on the heel bone; this joint tilts the heel in (inversion) and out (eversion) to cope with uneven ground.
• Midfoot (midtarsal) joints: flexible when the heel tilts out, locking when it tilts in, which turns the foot into a rigid lever for push-off.
• Tarsometatarsal (Lisfranc) joints: little movement, mostly stability; the second metatarsal is keyed into the midfoot.
• Toe joints: the big toe bends up at every push-off.

Sources 4, 1, 2, 14

Ligaments

Three ligaments brace the outside of the ankle; the front one (the anterior talofibular ligament) is the weakest and the most often sprained. On the inside, the fan-shaped deltoid ligament resists the sole turning outwards (eversion). Above the ankle, ligaments hold the two shin bones together, and these are what a "high ankle sprain" injures. Under the arch, the spring ligament supports it, together with the tibialis posterior tendon.

Sources 4, 1

The foot's own muscles

Inside the foot, 19 small (intrinsic) muscles sit in layers, mostly on the sole. They support the arches and move the toes. They don't have a muscle guide of their own yet.

Sources 1, 15

The plantar fascia and the load on the big toe

The plantar fascia is a thick band running from the heel to the toes along the sole. At push-off, load moves to the big-toe side of the forefoot, and the big toe joint carries about 119% of body weight with each step.

Sources 7, 16, 1

Three arches

The inner (medial longitudinal) arch is the highest and has the most joints, so it is the most mobile and shock-absorbing. The outer (lateral longitudinal) arch is lower and stiffer, which suits it to carrying weight and pushing off. The transverse arch runs across the midfoot. Bone shape, ligaments, the plantar fascia and the foot's muscles hold them up.

Sources 5, 6, 1

The windlass

At push-off your big toe bends up, winding the plantar fascia around the head of the first metatarsal like a rope around a winch. That tightens the fascia and raises the arch, so the foot becomes a stiff lever just when you need one.

Sources 1, 7

How arches develop

Babies look flat-footed, partly because of a fat pad under the arch. The NHS says most children develop arches between 3 and 10; other sources put it at 5 to 6, at 7 to 10, or at 10 to 12 for the full adult shape.

Sources 17, 6, 18, 19

Flat feet are common

About 20% to 37% of people have some degree of flat foot, mostly the flexible kind, where the arch reappears when the foot is off the ground. The NHS says flat feet are usually nothing to worry about. Trials of treatments for flat feet in children are too limited to draw conclusions.

Sources 18, 17, 20

Up and down

In the CDC (US Centers for Disease Control and Prevention) study of 674 healthy people, measured passively with the knee bent, adults pulled the foot up (dorsiflexion) about 12 to 14 degrees and pointed it (plantarflexion) about 49 to 62 degrees; women pointed further than men. With the knee straight, pulling the foot up is more limited, because the gastrocnemius crosses the knee.

Sources 21, 22, 4

Tilting in and out: it depends how you measure

In one study of 30 adults (about a third with a past ankle injury), the same ankles were measured two ways. Sitting, measured from the front of the foot, the sole turned in (inversion) about 31 to 33 degrees and out (eversion) about 10 to 11. Lying face down, measured at the heel, it turned in about 15 to 16 degrees and out about 8 to 9.

The sitting method includes the forefoot, which is why it gives about 43 degrees in total against 24 lying down. Neither figure is wrong; they measure different things.

Source 23

The big toe

In 33 people, the big toe bent up about 42 degrees during walking and about 58 degrees in a heel raise.

Source 24

How range changes with ageStrong evidence

Ankle range peaks in childhood and the teens and is lowest after 60, falling more in women. In the CDC data, pulling the foot up fell from about 23 to 25 degrees in children aged 2 to 8 to about 12 in adults aged 45 to 69.

Sources 21, 25, 26

A calf strength checkEmerging evidence

Healthy adults aged 20 to 59 averaged about 28 single-leg heel raises (203 people), and the authors set 25 as the mark of normal. In a later study of 566 adults standing on a 10-degree slope, the median was 24 for men and 21 for women, and women over 60 did better than men of the same age.

Sources 27, 28

Foot muscles get stronger with trainingEmerging evidence

In 57 runners, walking in minimalist shoes (building up steps each week) or doing foot exercises at least 5 days a week increased foot muscle size and strength over 8 weeks, and the shoes did as well as the exercises. A review of 28 trials (1,399 people) found minimalist shoes and foot exercises increased foot strength, at low to very low certainty.

Sources 8, 29

Six months in minimal shoes built toe strengthEmerging evidence

In 46 young adults, those who wore minimal shoes for most of the time they wore shoes, 6 days a week, increased toe-flexor strength by 57% over 6 months. The study wasn't described as randomised, and the shoes were supplied by the manufacturer.

Source 30

Lifelong minimal footwear goes with stronger archesEmerging evidence

Men who had worn minimal sandals all their lives had arches 9% higher and 27% stiffer than US men in conventional shoes, and bigger foot muscles; 1% had low arches, against 31% of the US men. A comparison like this can't prove that shoes caused the difference.

Source 19

Arch training: small changesEmerging evidence

In 21 people, 4 weeks of short-foot training (drawing the arch up without curling the toes) reduced how far the arch dropped by about 2 mm. In a review of 4 trials, arch movement changed after 8 weeks but not 4, and function and balance improved.

Sources 31, 32

Foot strengthening may reduce running injuriesEmerging evidence

In 118 recreational runners, an 8-week foot and ankle strengthening course followed by remote training cut running injuries over a year: the runners who didn't do it were about 2.4 times as likely to be injured. It is one trial.

Source 33

Balance training prevents ankle sprainsStrong evidence

Across 7 trials (3,726 people in sport), balance (proprioceptive) training cut ankle sprains by about a third, most clearly in people with a previous sprain. After a sprain, an 8-week home balance-board programme cut repeat sprains from 33% to 22% over a year in 522 athletes.

Sources 12, 13

Strong, comfortable feet help older people stay uprightEmerging evidence

In older people, weak toes, stiff ankles and disabling foot pain predicted falls. In 305 people aged about 74 with foot pain, a podiatry programme that included home foot and ankle exercises three times a week cut falls by 36%, though the number of people who fell didn't change significantly.

Sources 34, 35, 36

Flat feet usually need nothingStrong evidence

The NHS says flat feet are common, usually nothing to worry about, and shouldn't stop you doing any activity, including sport. Insoles, stretches and exercises can help pain or stiffness, but they won't change the shape of your feet.

Source 17

Flat feet and injuries: a small linkEmerging evidence

Across 21 studies (6,228 people), a rolled-in (pronated) foot was a small risk factor for shin splints and possibly kneecap pain, and wasn't linked with other foot, ankle or bone-stress injuries.

Source 37

Switching raises injury riskEmerging evidence

In 103 runners training for a 10 km race over 12 weeks, those in partly minimalist shoes had the most injuries, and fully minimalist shoes brought more shin and calf pain. A review of 7 studies (313 runners) linked switching with a moderate rise in injury risk, mostly bone stress in the forefoot, Achilles pain and calf pain, and suggests a supervised change over at least 12 weeks.

Sources 9, 10

Minimalist shoes haven't been shown to prevent injuriesMixed evidence

A Cochrane review of running shoes (12 trials, 11,240 people) found that cushioned and minimalist shoes may make little or no difference to injury rates (5 trials, 766 runners, low certainty). It found no trial comparing running shoes with non-running shoes, and most of its evidence was low or very low certainty.

Source 11

Short-term balance gainsEmerging evidence

In 28 young adults, 4 weeks of walking in minimalist shoes (3,000 rising to 5,000 steps a day) improved single-leg balance and foot posture, and the gains were still there 4 weeks after stopping.

Source 38

Knee arthritis: early signs of benefitEmerging evidence

In 56 older women with knee arthritis, 6 months of flexible minimal shoes for at least 6 hours a day reduced pain and lowered the load on the knee compared with their usual shoes. In a lab study of 75 people with knee arthritis, walking barefoot lowered peak knee load by about 12%.

Sources 39, 40

Back pain and posture: no trials

We found no trial of barefoot or minimalist shoes for back pain or whole-body posture, so claims that they fix either are unproven.

Our take

Minimalist shoes and time barefoot can strengthen feet, but whether they prevent injuries is unproven, and switching raises the risk. Build up over months, add foot and calf strength work first, and protect your feet if you have diabetes or numb feet.

Sources 8, 10, 11

Train toes, arches and calves about 3 times a week

Our editorial starting point: towel toe curls, the short-foot exercise and calf raises about 3 times a week, as in the foot programmes in trials, which mostly used 5-second holds and progressed from sitting to standing.

Sources 32, 8, 36

Keep the ankle's range

Ankle range falls after 60. Knee-to-wall rocks (10 slow rocks each side daily, the dose on the move's page) and calf stretches with the knee straight and bent help keep it (our editorial suggestion).

Sources 25, 21

Practise balance

Stand on one leg, barefoot, for 30 seconds at a time, next to a counter, and make it harder over the weeks: eyes closed, or on a cushion. After a sprain, our ankle sprain guide has a staged balance plan.

Sources 12, 13

Check your calves

Aim for about 25 single-leg heel raises in a row as a long-term marker, building up with 2 sets of 10 to 15 slow calf raises (the dose in our workouts). Fewer is a reason to train, not to worry.

Source 27

With diabetes or numb feet

Check your feet after barefoot work, and see a GP about any foot pain: the NHS notes that foot problems can be more serious if you have diabetes.

Source 41

Foot and ankle pain

Our foot pain and ankle pain guides sort it by where it hurts, with the rules doctors use to decide whether a twisted ankle needs an X-ray.

Sprains and unstable ankles

Most sprained ankles recover with early movement, but many sprain again; an ankle that keeps giving way has its own guide.

Heel, Achilles, shin and calf

Plantar fasciitis (heel pain), Achilles tendinopathy, shin splints and calf pain each have a guide. One swollen, warm calf needs a same-day check.

Arthritis

Ankle arthritis usually follows an old injury, and big toe arthritis makes the joint stiff and painful.

The forefoot

Ball of foot pain covers metatarsalgia and Morton's neuroma. Exercises may ease bunion pain but are unlikely to straighten the toe.

Flat feet

Most need no treatment, but an arch that flattens in one foot can be a tendon problem worth checking.

Get help from NHS 111

If you have severe ankle pain; you feel faint, dizzy or sick from the pain; your ankle or foot has changed shape or is at an odd angle; you heard a snap, grinding or popping noise at the time of injury; or you're not able to walk. These can be signs of a broken ankle or an infection. In the US, contact your doctor or urgent care.

Source 41

See a GP

If ankle pain is stopping you doing normal activities, is getting worse or keeps coming back, or hasn't improved after treating it at home for 2 weeks; if you have any tingling or loss of feeling in your foot; or if you have diabetes and foot pain, as foot problems can be more serious with diabetes.

Source 41

Flat feet: see a GP

If your feet are painful, stiff, weak or numb; you often get foot or ankle injuries; you have problems with walking or balance; you didn't have flat feet before; or only one foot is affected.

Source 17

A painful, swollen calf

Throbbing pain in one leg, usually in the calf or thigh, with swelling, red, blue or darkened skin around the painful area, or swollen veins: ask for an urgent GP appointment or get help from 111. If you also feel short of breath or have chest pain, call 999 (911 in the US).

Source 42

While you exercise

Stop the bounces and hops for heel, Achilles or shin pain that builds, and check your feet afterwards if they're numb (our editorial advice, as on each move's page).

"The foot has 26 bones, full stop"

That's the usual count. Add the two sesamoids under the big toe and it's 28, and extra small bones are common.

Sources 3, 14

"Flat feet are a problem to fix"Strong evidence

Painless flat feet need no treatment, and exercises don't change the shape of the foot.

Source 17

"Barefoot shoes prevent injuries"Mixed evidence

That hasn't been shown, and runners who switched to minimalist shoes had more injuries.

Sources 11, 10, 9

"Shoes make your feet weak"Emerging evidence

People who have always worn minimal footwear have stronger, stiffer feet, and feet get stronger when people switch, but a difference between groups doesn't prove that ordinary shoes cause weakness.

Sources 19, 8, 30

"Foot exercises will build an arch"Emerging evidence

They reduce how far the arch drops by about 2 mm and change arch movement after about 8 weeks, but they haven't been shown to change the shape of a flat foot.

Sources 31, 32, 17

"A sprained ankle is never the same"Strong evidence

Balance training cuts repeat sprains. Our chronic ankle instability guide covers ankles that keep giving way.

Sources 12, 13