Stand near a wall and try rising onto the toes of one foot. Then compare it with the other side.
If the heel will not lift properly, or the movement causes pain along the inside of the ankle, the tibialis posterior tendon may be involved. This tendon helps hold up the arch and supports the foot during push-off.
This guide explains tibialis posterior tendinopathy, how it causes inner ankle pain, what the different stages mean and how the condition is assessed and treated. The way clinicians classify it has evolved, including a revised classification published in 2020, but the central question remains the same: is the tendon still working, and has the foot shape started to change?
What is tibialis posterior tendinopathy?
The tibialis posterior muscle sits deep in the calf. Its tendon travels behind the inner ankle bone, called the medial malleolus, before attaching across the midfoot. It helps hold up the arch and turns the foot inward during push-off.
You may also see the condition called posterior tibial tendonitis, tib post tendinopathy or posterior tibial tendon dysfunction (PTTD). “Tendinopathy” is often the most useful term because the problem is not always simple inflammation. The tendon fibres can become disorganised and thickened, and the tendon may gradually lose its ability to support the arch.
What does tibialis posterior tendinopathy feel like?
The usual first symptom is an ache along the inside of the ankle or inner foot that develops over several weeks.
Inner ankle pain
The tender area is often just below the bony bump on the inside of the ankle and can be traced behind it towards the arch.
Swelling
Fullness or swelling may follow the same line as the tendon.
Load-related symptoms
Pain is usually worse with prolonged standing or walking and easier when sitting.
Weak heel raise
Rising onto the toes of the affected foot may feel painful, weak or impossible.
Changing foot shape
At later stages, the arch can flatten, the heel drifts outward and more toes become visible from behind.
The last sign is sometimes called the “too many toes” sign. It happens as the forefoot turns outward relative to the heel.
Why does it happen?
The condition develops when the load placed on the tendon exceeds its capacity to recover. The section of tendon passing behind the inner ankle also has a relatively limited blood supply, which may reduce its ability to repair repeated strain.
Published estimates suggest it affects more than 3% of women over 40 in the UK and around 10% of older patients. The typical presentation is a woman in her sixth decade. In one clinical series, 81.5% of patients had a body mass index of 25 or above.
Other recognised associations include high blood pressure, diabetes, a previous ankle injury and steroid exposure. Runners and frequent walkers can also develop symptoms after increasing their training volume or changing surface, footwear or intensity too quickly.
Inner ankle pain can overlap with other foot and heel conditions. Read our guide to heel pain, plantar fasciitis and Achilles tendinopathy.
How is tibialis posterior tendinopathy diagnosed?
Assessment starts with the location of the pain, the shape of the foot and movement tests.
- Tenderness and swelling may be present behind the medial malleolus.
- During a single-leg heel raise, a healthy heel lifts and swings inward. On the affected side, the movement may be painful, weak or impossible.
- Viewed from behind, a flattened arch and outward-turning forefoot can create the “too many toes” sign.
These signs can strongly suggest tendon dysfunction, but examination alone cannot reliably show whether the main problem is inflammation around the tendon, internal degeneration or a partial split. Imaging helps answer that question.
Inner ankle pain lasting more than a few weeks deserves assessment
This is particularly important if the arch appears to be dropping or a single-leg heel raise is becoming difficult.
Foot & Ankle UltrasoundWhat are the stages?
The traditional staging system describes how tendon failure progresses from irritation to a fixed deformity. Newer classifications give clinicians more detail, but these four stages remain an accessible way to understand the condition.
| Stage | What is happening | Typical finding |
|---|---|---|
| Stage I | The tendon is inflamed or degenerative but still working. | A heel raise is possible and the foot shape remains normal. |
| Stage II | The tendon has lengthened and the arch has started to collapse. | The heel raise is difficult and the flatfoot remains flexible. |
| Stage III | The flatfoot deformity has become rigid. | Arthritis develops in joints below the ankle. |
| Stage IV | The deformity has progressed into the ankle. | The ankle joint begins to tilt. |
Swipe sideways to view the complete table.
Not sure which stage applies?
The Joint Pain Clinic can combine imaging findings with a clinical assessment and appropriate treatment pathway.
Joint Pain ClinicWhat does a foot and ankle ultrasound show?
Ultrasound examines the tendon in real time and can follow it around the curve of the inner ankle while the foot moves.
A healthy tendon has an organised striped appearance. A worn tendon may look thickened, darker and less organised, sometimes with fluid around it.
Tenosynovitis
Fluid and inflammation around the tendon sheath.
Tendon degeneration
Thickening and disruption of the normal fibre pattern.
Partial tears
Splits or focal defects within the tendon.
Spring ligament failure
Damage to another important structure supporting the arch.
For an early-stage problem, ultrasound can often answer the key questions quickly. MRI may be recommended when a significant tear is suspected or surgery is being considered.
Find the stage before choosing treatment
Imaging helps separate irritation around a functioning tendon from degeneration, splitting and loss of arch support.
How is tibialis posterior tendinopathy treated?
Treatment depends on the stage and what imaging shows.
Orthoses and supportive footwear
Supporting the arch is the foundation of early treatment. An orthosis reduces strain on the tendon while supportive footwear helps control the heel and midfoot.
Progressive strengthening
Exercise helps rebuild the tendon’s capacity. In a randomised trial of 36 adults with stage I or II disease, all groups improved with orthoses and stretching, but adding strengthening produced better results. The eccentric strengthening group improved the most, while orthoses and stretching alone improved the least.
A personalised rehabilitation programme can progress from resisted inward movement of the foot to controlled heel raises, according to pain and function.
Short-term rest or immobilisation
When symptoms are more irritable, a walking boot for three to four weeks may allow the tendon to settle before rehabilitation begins.
Injections
Steroid exposure is a recognised risk factor, so corticosteroid must be used cautiously and should not be injected into the tendon itself. If clinically appropriate, an ultrasound-guided corticosteroid injection may be placed into the tendon sheath rather than the tendon.
Surgery
Surgery becomes more likely after the tendon has lengthened and the arch has collapsed, particularly when the deformity is progressing or becoming rigid. A consultant orthopaedic assessment can clarify the appropriate pathway.
Is walking okay with tibialis posterior tendinopathy?
Walking is usually acceptable in supportive shoes and within a comfortable symptom level. Avoid long distances, hills, uneven surfaces and walking barefoot on hard floors while the tendon is painful.
If the arch appears to be dropping, the heel position is changing or walking tolerance is steadily worsening, arrange an assessment rather than trying to push through it.
How long does recovery take, and is it permanent?
Recovery usually takes months rather than weeks and depends heavily on the stage.
Early-stage disease can often improve over three to six months with orthoses, supportive footwear and progressive strengthening, while preserving the shape of the foot.
Once the tendon has lengthened and the arch has collapsed, the foot shape does not simply reverse on its own. The deformity may initially remain flexible and later become rigid, and can be permanent without surgery. Pain can still improve at any stage with the right management.
Book an assessment with London Private Ultrasound
Inner ankle pain is often dismissed as a minor strain. Earlier diagnosis matters because treatment is more straightforward while the tendon is still functioning and the arch shape is preserved.
Dynamic ultrasound
The tendon is assessed in real time, including its sheath, fibre pattern and movement.
Experienced clinicians
Your scan is performed and interpreted by an experienced sonographer, with findings explained during the appointment.
Joined-up care
If further medical input is needed, the report can be shared with your GP. Rehabilitation, injections and orthopaedic assessment are available in the same building.
Convenient appointments
Same-day and next-day appointments are available seven days a week, 9am to 7pm, in the Harley Street medical district and St Albans.
What you can book
A foot and ankle scan can assess the tibialis posterior tendon alongside the Achilles tendon, plantar fascia, ankle ligaments, peroneal tendons and tarsal tunnel. For activity-related symptoms, a sports injury scan offers a focused MSK assessment.
Related musculoskeletal services
Foot and ankle ultrasound
Dynamic assessment of tendons, ligaments, plantar fascia, tarsal tunnel and other accessible soft tissues.
Foot & Ankle UltrasoundAnkle ultrasound
A focused scan for pain, swelling or suspected soft-tissue injury around the ankle.
Ankle UltrasoundPersonalised rehabilitation
A progressive programme matched to your diagnosis, symptoms and functional goals.
Rehabilitation ProgrammeOrthopaedic assessment
Specialist review when arch collapse, significant tendon failure or surgery needs consideration.
Orthopaedic AssessmentJoint Pain Clinic
Integrated clinical assessment, imaging and treatment for musculoskeletal pain.
Joint Pain ClinicOne-Stop Orthopaedic MSK Clinic
Combined specialist musculoskeletal assessment and imaging in one coordinated pathway.
One-Stop MSK ClinicFrequently asked questions
How do you get rid of tibialis posterior tendinopathy?
Early treatment usually combines arch-supporting orthoses, supportive footwear, temporary activity changes and progressive strengthening. In a randomised trial, adding strengthening improved outcomes, with eccentric exercise producing the greatest improvement.
How long does tibialis posterior tendinopathy take to heal?
Early-stage problems often need three to six months of consistent support and rehabilitation. Later-stage disease can take longer and may require surgery when the arch has collapsed.
Is walking okay with tibialis posterior tendinopathy?
Usually yes, provided you wear supportive shoes and stay within a comfortable symptom level. Avoid long distances, hills, uneven ground and walking barefoot on hard floors during a painful phase.
Is tibialis posterior tendinopathy permanent?
Pain can improve at any stage. However, once the tendon has lengthened and the arch has flattened, the change in foot shape can be permanent without surgery.
What test checks the tibialis posterior tendon?
The single-leg heel raise is a useful clinical test. A painful, weak or impossible heel raise raises suspicion, while ultrasound can show tendon thickening, degeneration, sheath inflammation and partial tears.
Which exercises help?
Rehabilitation often progresses from resisted inward movement of the foot with a band to controlled double- and single-leg heel raises. The programme should be adjusted to your stage and symptoms.
Is tibialis posterior tendinopathy the same as shin splints?
No. Shin splints usually cause pain along the inner border of the shin bone. Tibialis posterior tendinopathy causes pain and sometimes swelling around or below the inner ankle bone and may change the arch shape.
Do I need a GP referral for an ultrasound?
No. You can book a private foot and ankle ultrasound directly. Your report can be shared with your GP, physiotherapist or consultant if needed.