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Tibialis Posterior Tendinosis and Tibialis Posterior Tenosynovitis


James C. Connors

, DPM, Kent State University College of Podiatric Medicine

Reviewed/Revised Dec 2023

Tibialis posterior tendinosis is wear and tear of the tendon that passes behind and around the inner side of the ankle (called the tibialis posterior tendon). Tibialis posterior tenosynovitis is inflammation of the protective covering around the tendon (called the tendon sheath).

  • The tibialis posterior tendon may become damaged or inflamed.

  • Pain of varying degrees is felt around the ankle.

  • The diagnosis is usually based on symptoms and an examination and sometimes imaging tests.

  • Depending on the disorder, orthoses and surgery or therapy to relieve inflammation can help.

The tibialis posterior tendon helps maintain the normal arch of the foot.

Tibialis posterior tendinosis is usually caused by an excessive ongoing strain caused by a problem with the way the foot moves. Most often, the person has a low arch, and the foot tends to turn outward when walking and appears flat when standing. Tendon dysfunction may further contribute to flattening of the arch. The tendon may tear completely in older adults and in people who had a previous injury or have chronic dysfunction. Tendon rupture may be a cause of tibialis posterior tendinosis in a young person with sudden arch collapse.


In tibialis posterior tendinosis, early on people have occasional pain behind the inner ankle with increased activity. In time, the pain becomes severe, and swelling occurs. Normal standing and walking become more difficult. Standing on the toes is usually painful and may be impossible if the tendon is completely torn. If the tendon tears completely, the foot may suddenly flatten (called arch collapse) and pain may be felt in the sole.

In tibialis posterior tenosynovitis, pain typically occurs suddenly and the tendon may feel thick and swollen as it winds around the bump on the inside of the ankle (medial malleolus).

In some cases when the tendinosis has been long-standing, the arch of the foot may gradually fall, and the foot will appear flatter. These bony changes can also cause osteoarthritis in some of the bones of the foot and may progress to the ankle.


  • A doctor's examination

  • Sometimes x-ray or MRI (magnetic resonance imaging)

Doctors can often base the diagnosis on the person’s symptoms and the results of an examination. However, sometimes an x-ray or MRI Computed tomography (CT) and magnetic resonance imaging (MRI) A doctor can often diagnose a musculoskeletal disorder based on the history and the results of a physical examination. Laboratory tests, imaging tests, or other diagnostic procedures are sometimes... read more Computed tomography (CT) and magnetic resonance imaging (MRI) is necessary to rule out other causes of ankle pain, confirm the diagnosis, and to see the extent of tendon damage.


  • For tibialis posterior tendinosis, orthoses and braces or surgery

  • For tibialis posterior tenosynovitis, anti-inflammatory therapy

For tibialis posterior tendinosis, devices placed in the shoe (orthoses) and ankle braces worn with supportive shoes or boots are usually sufficient. Complete tears are treated surgically so people can function normally again. Surgery is especially important in young active people with tears that develop suddenly.

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