What is Tibialis Posterior Tendinopathy?
Tibialis posterior tendinopathy (also referred to as posterior tibial tendon dysfunction (PTTD)), is a progressive, overuse injury affecting the foot and ankle. It is the most common cause of adult-acquired flat foot deformity.
Classically this condition is seen in runners. However, it is also common in middle-aged females and people suffering from diabetes, obesity, high blood pressure or those who have had previous foot surgery.
What is the tibialis posterior?

The tibialis posterior is an important muscle lying deep in your calf. It plays an essential role in controlling the arch of the foot and allowing you to toe-off during walking, running and jumping. It runs from the back of the tibia (shin) bone, down the inside of the ankle, and attaches to the navicular bone (one of the bones in the inside arch of the foot). It helps to point and turn the foot inwards.
Common causes & symptoms
As tibialis posterior tendinopathy is usually an overuse or repetitive strain injury there are certain common activities which can cause pain:
- Running
- Walking long distances
- Walking on uneven terrain
- Using less supportive footwear e.g sandals
Symptoms often include:
- Aching/burning pain around the inside of the ankle
- Swelling over the inside ankle/lower calf
- Pain when running
- Pain on first steps in the morning
- Pain with stairs
- Pain wearing flat shoes
- Ankle pain +/- stiffness
- Inability to raise onto your toes
- Weakness/instability around the ankle
- Flat foot posture
Tibialis Posterior Tendinopathy (or PTTD) Stages
PTDD is a progressive condition that has been classified into 4 stages by Johnson & Strom.
Stage 1 | Pain +/- swelling along the tibialis posterior tendon. No structural change to foot posture. Able to perform a single leg calf raise (SLCR) |
Stage 2a | Pain +/- swelling along the tibialis posterior tendon. Marked weakness. Tendon degeneration/tearing. Unable to SLCR. Flat foot posture (correctable) |
Stage 2b | As per 2a with addition of forefoot abduction |
Stage 3 | As per 2b but uncorrectable deformity of foot and degenerative changes rear foot |
Stage 4 | As per 3 with additional ankle deformity and osteoarthritis |
Tendinopathy or Tendinitis?
As used in many medical terms, ‘itis‘ is latin for inflammation. So tibialis posterior tendinitis basically means inflammation of the tendon. ‘Opathy’ is latin for ‘disorder of’, which better describes the overall injury as over time it will go through different stages. Hence the term tibialis posterior tendinopathy. Due to a poor blood supply and repetitive strain nature, tendons take time to heal. Usually months.
What’s going on?

Tendons (and in general all soft tissues) are in a constant continuum of healing. When a tendon becomes painful in the first 3-6 weeks, be it a first time episode or a flare up of a persistent problem, we class this as the ‘reactive phase’. Typically when symptoms are more acute and irritable. For example, each step when walking or going up/down stairs.
Have patience
Over time the inflammation becomes more degenerative in nature due to a build up of scar tissue. This is termed as a ‘disrepair’ of the natural healing process. Tibialis posterior tendinopathy symptoms in this phase include pain that is worse when walking over time or trying to run.

Diagnosis
One simple way to establish what stage of healing the tibialis posterior tendon is in, and provide diagnosis confirmation is using ultrasound scans. Take a look here for more information on our specialist diagnostic ultrasound service.
Our next blog explains the best treatment options for tibialis posterior tendinopathy.
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