Posterior Tibial Tendinitis

Overview

Posterior tibial tendinitis is irritation, inflammation, or gradual wear of the posterior tibial tendon. This tendon runs along the inside of the ankle and foot and plays a key role in holding up the arch and supporting the foot when you walk. When it becomes damaged, the arch can begin to lose support.

This condition is a leading cause of adult-acquired flatfoot. Catching it early is important, because untreated tendon dysfunction can progress and lead to a gradual flattening of the arch that becomes harder to correct over time. The broader, more chronic form is often called posterior tibial tendon dysfunction.

Symptoms

Symptoms usually develop gradually and affect the inner side of the foot and ankle:

• Pain and tenderness along the inside of the ankle and arch
• Pain that worsens with activity, such as walking, running, or standing for long periods
• Swelling along the inner ankle
• A gradual flattening of the arch of the foot
• The foot and toes turning outward over time
• Difficulty standing on tiptoe on the affected foot
• As the condition progresses, pain may shift to the outer side of the ankle

Causes

The condition results from overloading or repeated strain on the posterior tibial tendon, which causes inflammation or small tears that weaken it over time.

It can develop from overuse during sports and activity, a sudden injury, or gradual wear with age. Because the tendon has a limited blood supply in places, it can be slow to heal, and ongoing stress can lead to progressive damage and loss of arch support. Doctors often describe the condition in stages, ranging from early inflammation with a flexible foot to later stages where the arch has flattened and the foot becomes stiff. Knowing the stage helps guide treatment, since earlier stages usually respond well to non-surgical care.

Risk Factors

• Middle age and older, particularly in women
• Excess body weight
• Activities that stress the tendon, such as running, hiking, or sports with quick changes of direction
• Flat feet or low arches
• High blood pressure, diabetes, or other conditions affecting circulation
• Previous ankle injury

Diagnosis

Diagnosis is based on examination of the foot and ankle, with imaging when needed.

• Physical exam: checking for tenderness and swelling along the tendon, arch height, and foot alignment
• Single-leg heel raise test: difficulty rising onto the toes on the affected foot suggests tendon weakness
• Imaging: X-rays to assess foot alignment and ultrasound or MRI to look at the tendon directly

Treatment

Early treatment is mostly non-surgical and aims to rest the tendon and support the arch.

• Rest and activity changes: reducing activities that aggravate the pain
• Immobilization: a brace, walking boot, or cast for a period to let the tendon settle in more significant cases
• Orthotics and supportive shoes: custom insoles or arch supports to take load off the tendon
• Physical therapy: strengthening and stretching exercises to support the arch
• Ice and pain relief: to manage inflammation and discomfort

If the condition is advanced or does not improve, surgery may be considered to repair the tendon or correct foot alignment. Early care offers the best chance of avoiding this. Recovery often takes time and requires consistency with supportive footwear and exercises, even after the pain settles. Because the tendon can be slow to heal, returning to high-impact activity too soon may cause the problem to flare again, so a gradual return guided by your clinician is usually best.

Prevention

• Wear supportive footwear and replace worn-out shoes
• Use arch supports or orthotics if you have flat feet
• Build up exercise intensity gradually and stretch before activity
• Maintain a healthy weight
• Address inner ankle or arch pain early rather than pushing through it

When to See a Doctor

See a doctor if you have ongoing pain or swelling along the inside of your ankle or arch, especially if you notice your arch flattening or your foot turning outward. Early evaluation matters because the condition can worsen. Also seek care if you:

• Cannot stand on tiptoe on the affected foot
• Have pain that does not improve with rest and supportive shoes
• Notice a progressive change in the shape of your foot
• Have diabetes or poor circulation with foot pain or swelling

Related Topics

Frequently Asked Questions

References

1. American Academy of Orthopaedic Surgeons (AAOS). Posterior Tibial Tendon Dysfunction.
2. American College of Foot and Ankle Surgeons.
3. MedlinePlus, U.S. National Library of Medicine. Foot and ankle pain.
4. Mayo Clinic. Flatfeet.