Pain guide · Ankle pain
The posterior tibial tendon runs behind the bony bump on the inside of the ankle and holds up the arch. When it is overloaded it hurts and swells along the inner ankle, rising onto tiptoe gets hard, and over time the arch can drop, often on one side. It's called posterior tibial tendonitis or posterior tibial tendon dysfunction (PTTD), and surgeons now group it under progressive collapsing foot deformity.
A new or one-sided flat foot needs a GP check. Most people improve without surgery, with insoles or a brace and exercise, but the evidence for the exercises is thin: two small trials of 36 and 39 people. This guide explains the single-leg heel raise test, what the trials found and a staged plan with 3D demos.
Exercise is for pain that has been checked or is clearly mild and settling.
The tibialis posterior is a deep calf muscle. Its tendon runs behind the bony bump on the inside of the ankle and into the arch, and it is the main support of the inner arch. When the tendon is irritated, worn or torn, it can't hold the arch up as well: the arch can flatten, the heel tips outwards and the front of the foot drifts out.
Clinicians have long used four stages: 1, a sore tendon that still works; 2, a failing tendon with a flat foot that can still be corrected by hand; 3, a stiff flat foot with arthritis below the ankle; and 4, arthritis in the ankle too.
In 2020, a consensus of 9 surgeons voted unanimously to rename the whole range progressive collapsing foot deformity, because the problem is a complex change in foot shape that isn't always caused by the tendon. Only 3 of the 9 thought MRI (magnetic resonance imaging) findings should be part of the new stages.
Mostly women over 40. When women over 40 at an English GP practice were surveyed and examined, 3.3% had stage 1 or 2, and none had been diagnosed, despite long-standing symptoms. A clinical review suggests it may affect up to 10% of older women.
Risk factors include flat feet, high blood pressure, diabetes, a steroid injection near the tendon, inflammatory arthritis and being overweight. It is often missed: the same review says most people are first told they have a sprain or arthritis.
Standing on one leg and rising onto tiptoe needs a working tendon. A clinical review says someone with a normal foot can do about 8 to 10 single heel raises; with this problem it's hard or impossible, and the heel doesn't swing inwards. From behind, more toes show on the outside of the affected foot (the too many toes sign).
The test has limits. In 50 people, those with stage 2 didn't rise as high, but healthy older adults also rose less high than young adults, so expectations need adjusting for age. In a two-leg heel raise, people with stage 2 turned the heel in about as much as people without the problem, but their midfoot sagged instead of lifting (6.5 degrees of midfoot bend against 12 in controls), so a heel that turns in doesn't rule it out. Strength turning the foot in was 20% to 30% lower on the affected side.
The diagnosis is mainly clinical. X-rays taken standing show the shape of the foot and any arthritis, and an MRI scan can show inflammation or a tear. In one group of 64 people, a split tear on MRI went with treatment without surgery not working. No study of tendon changes on MRI in people without symptoms was found, so we can't say how often scans show changes that don't matter.
The foot shape can slowly change if nothing is done, but most people improve without surgery. An NHS-commissioned booklet says most cases resolve without surgery within 3 to 12 months. The American Academy of Orthopaedic Surgeons (AAOS) warns that pain can last more than 3 months even with early treatment, and that after many months of pain it is not unusual for it to last another 6 months once treatment starts. In 33 feet treated with a brace, about 70% were free of the brace without surgery 7 to 10 years later.
In a case series of 47 people with stage 1 or 2, a short ankle brace or a foot orthosis, with a high-repetition exercise programme at home and in clinic, led to good results in 83% after a median of 10 physiotherapy visits over about 4 months; 89% were satisfied and 11% needed surgery.
Across 4 small trials (186 people, most at high risk of bias), orthoses reduced pain in the early stages, especially with exercise, and orthoses with personalised arch support did better than flat insoles. In 64 people, 87.5% were treated without surgery over about 27 months, and wearing a brace went with success. The AAOS says most people in the early stages can be treated with orthoses and braces.
The evidence is thin. In a trial of 36 adults with stage 1 or 2, everyone wore orthoses and stretched for 12 weeks; adding resistance exercise helped, and the group whose exercise had a slow lowering phase improved most in pain and function. Their exercise swept the front of the foot inwards against resistance with the foot slightly pointed: 3 sets of 15 at a load they could only just manage, twice a day.
In a trial of 39 adults with stage 2, a home programme of heel raises and band work, from 2 sets of 10 to 3 sets of 30, twice a day, added little to an orthosis and stretching, and strength didn't change. A review of these and one other trial (93 people in all) called the research sparse, found people did about 68% to 79% of their sessions, and noted that 15 to 30 repetitions trains endurance rather than strength.
Every trial included calf stretches (3 to 10 holds of 30 s, 2 to 4 times a day), and the AAOS lists calf stretching as part of physiotherapy. But a review points out that holding the ankle fully bent up squeezes and stretches the tendon behind the ankle bone, which may work against easing the pain. So the plan here keeps stretching optional and gentle.
For a bad flare, a 2004 clinical review advises 4 to 8 weeks in a cast or removable boot, then orthoses and lace-up shoes. The AAOS mentions 6 to 8 weeks in a cast or boot, but warns that a cast weakens the leg muscles and keeps it for when other treatment hasn't worked. The trials above used orthoses and exercise without routine casting.
Steroid injections into the tendon are avoided: the 2004 review calls them contraindicated, the AAOS says they are not normally done because of the risk of the tendon rupturing, and an NHS-commissioned booklet says they are rarely advised.
Surgery is considered if pain persists after several months of good treatment, and an NHS-commissioned booklet says only after 6 months, and rarely. Operations range from cleaning the tendon sheath to moving another tendon to do its job, cutting and shifting the heel bone, and fusing joints. The AAOS says it takes 6 months or more before healing is complete and pain is much better.
Aim for discomfort no more than about 5 out of 10, settling within an hour and no worse the next morning. The 5 out of 10 figure is editorial, as on this site's other tendon pages, borrowing the pain-monitoring approach from an Achilles trial; it hasn't been tested in this tendon.
An NHS-commissioned booklet adds two practical rules: if an exercise is painful, do fewer or do them less often, and stop a heel raise or squat if you feel you're losing your foot position, then reset.
Start at the first stage. Each move opens a full guide with a 3D demo.
Wear the orthoses, brace or supportive lace-up shoes you've been given: the trials ran for 12 weeks with insoles worn throughout. Doses are marked with their source or are editorial.
3D demoBand ankle inversionBeginner · A band + A bench or box3 sets of 15 with a light band, once or twice a day · Sweep the front of the foot inwards with the foot slightly pointed: the format from the trial of 36 people; the light start is ours
3D demoSlow calf raiseBeginner · A wall2 sets of 10 on both feet, twice a day · The starting dose from the trial of 39 people. A soft ball held between the heels helps keep them turning in (an NHS-commissioned booklet)
Easier: Seated bent-knee calf raise (soleus raise) · Harder: Standing dumbbell calf raise
3D demoSeated bent-knee calf raise (soleus raise)Beginner · A bench or box3 sets of 15 · Editorial
Harder: Slow calf raise
3D demoSingle-leg standBeginner · A wall3 holds of 30 s each leg, near a support · Editorial
Easier: Tandem stance and heel-to-toe walk · Harder: Single Leg Reach Matrix
3D demoSeated calf stretch with a towelBeginner · Other / check instructionsOptional: 3 gentle holds of 30 s · Never forced to the end of the range, because holding the ankle fully bent up may squeeze the tendon
Move on when: 3 sets of 15 with a light band stay within the pain rule and have settled by the next morning.
Make the band work heavier, with a slow return, and build the number of heel raises. Doses are marked with their source.
3D demoBand ankle inversionBeginner · A band + A bench or box3 sets of 15 with a band you can only just manage, twice a day · Take 2 to 3 s to let the foot back: the slow lowering did best in the trial of 36
3D demoSlow calf raiseBeginner · A wallBuild from 2 sets of 10 to 3 sets of 30, twice a day · The trial of 39's progression; holding the top for up to 10 s is an NHS-commissioned booklet's version
Easier: Seated bent-knee calf raise (soleus raise) · Harder: Standing dumbbell calf raise
3D demoBodyweight squatBeginner · No equipment3 sets of 10 small squats · Keep the arches from collapsing, and stop if you lose your foot position (an NHS-commissioned booklet)
Easier: Sit squat (partial squat) · Harder: Dumbbell goblet squat
3D demoGlute bridgeBeginner · No equipment8 to 12 · An NHS-commissioned booklet's dose
Easier: Pelvic tilt into bridge · Harder: Glute kickback (quadruped hip extension)
3D demoClamshellBeginner · No equipment8 to 12 each side · An NHS-commissioned booklet's dose
Harder: Lateral band walk
Move on when: 20 or more two-leg raises are comfortable and within the pain rule.
Move to single-leg raises and heavier calf work, keep the insoles on, and build your walking. Doses are marked with their source or are editorial.
3D demoSingle-leg calf raise from a stepIntermediate · A step + A wall2 to 3 sets of 10, building to 30 · On flat ground first; the trial of 39's single-leg raises. Watch that the heel turns in and the arch stays lifted as you rise
Easier: Slow calf raise · Harder: Single-leg pogo hops
3D demoStanding dumbbell calf raiseIntermediate · A dumbbell3 sets of 8 to 12 · Editorial: the trials used 15 to 30 repetitions, which a review notes trains endurance rather than strength
Easier: Slow calf raise · Harder: Single-leg pogo hops
3D demoSingle Leg Reach MatrixIntermediate · No equipment3 rounds of 5 each direction · Editorial
Easier: Standing crossed-leg side reach · Harder: Single-leg Romanian deadlift
3D demoTreadmill walkingBeginner · Cardio machineBuild your walking time · In your insoles; editorial
Harder: Treadmill jogging
Move on when: Single-leg raises are comfortable. In one case series of 47 people, the targets for finishing physiotherapy were 50 single-leg heel raises with little or no pain and walking about 30 m on tiptoe: a long-term goal, not a test. Keep strength work going twice a week (our suggestion), and if pain persists after about 6 months of good treatment, ask about a referral.
This NHS-commissioned exercise suits stages 1 and 2. The site doesn't demonstrate it yet, so here are the steps.
Source 2
Supportive lace-up shoes, or walking boots that support the arch and ankle if you're on your feet for long; leave out flip-flops and other unsupportive footwear. A podiatrist can provide orthoses for your foot. A simple lace-up ankle brace may help mild to moderate cases, and heavier custom braces can help people with severe, stiff flat feet avoid surgery.
Cut back the standing, walking, running and jumping that hurt, and swap to cycling, an elliptical trainer or swimming. A cold pack for 20 minutes, 3 or 4 times a day, can ease swelling. Losing weight, if you need to, takes stress off the arch.
| Habit or position | Why it matters | Instead |
|---|---|---|
| Ignoring a foot that is flattening on one side | The NHS says new or one-sided flat feet need a GP, and the foot shape can slowly change. | Get it assessed, and wear insoles or a brace as advised. |
| The tibialis posterior stretch with a strap, or other hard stretches at the inner ankle | Holding the ankle fully bent up may squeeze the sore tendon. | Gentle, optional calf stretches.Try: Seated calf stretch with a towel |
| Flip-flops, flat or unsupportive shoes | An NHS-commissioned booklet advises against them. | Supportive lace-up shoes or walking boots. |
| Long spells of standing, running and jumping during a flare | Pain worsens with weight-bearing and impact. | Cycling, swimming and shorter walks.Try: Stationary cycling |
| A steroid injection into the tendon | It carries a risk of the tendon rupturing. | Orthoses and exercise. |
| Heel raises done while the arch collapses | An NHS-commissioned booklet says stop if you lose your foot position. | Fewer repetitions with the arch held; a soft ball between the heels helps. |
A 15-minute barefoot routine for stronger toes, arches, calves and ankles, finishing with balance. You need only a towel, a wall and a resistance band.
15 minBeginner11 movesA wall, Other / check instructionsBalance practice in 10 minutes: tandem stance, single-leg stands, marches, heel walks, tree pose and floor transfers.
10 minBeginner7 movesA wall, A bench or boxStrength and balance in one session: squats, Romanian deadlifts, push-ups, rows, step-ups, back extensions, carries and single-leg balance.
45 minBeginner14 movesA wall, A dumbbellA painful, weakened tendon on the inside of the ankle that normally holds up the arch. Over time the arch can drop, which surgeons now call progressive collapsing foot deformity.
Pain and swelling behind the inner ankle bone and along the instep, aching on long walks, difficulty rising onto tiptoe, and a foot that looks flatter than the other. Later, pain can spread to the outside of the ankle as the foot shape changes.
Standing on the painful leg and rising onto tiptoe. Most people manage about 8 to 10; with this problem it's hard or impossible, and the heel doesn't swing in. Older adults rise less high anyway, so a clinician should judge it.
Sweeping the front of the foot inwards against a band and letting it back slowly, alongside insoles and stretching, helped most in a trial of 36 people. Heel raises on both feet and then on one were part of another trial's home programme, which added little to insoles and stretching. The evidence is thin, but these are the best-tested exercises.
Usually, yes, early on. Arch-supporting orthoses eased pain in small trials, and wearing a brace went with avoiding surgery in one group of 64 people.
The trials ran for 12 weeks, and one centre's programme took about 4 months of physiotherapy. Most people improve within 3 to 12 months, though pain can last more than 3 months even with early treatment.
Gently, if at all. Hard stretches that bend the ankle fully up may squeeze the tendon.
Most people don't: in one group, about 70% were free of their brace without surgery 7 to 10 years later. Surgery is considered after about 6 months of good treatment without surgery.
No. Most flat feet are normal and need no treatment. This is a painful tendon that makes a foot flatten, often on one side, and it needs assessing.
Yes, in supportive shoes and your insoles, within the pain rule. Swap running and jumping for cycling or swimming during a flare.
Exercise education, not a diagnosis or treatment plan. It is written from the guidelines and studies listed above; review by a clinician is pending. If your pain follows an injury, is severe, is getting worse, or comes with any warning sign listed on this page, get it assessed. Health disclaimer.
