Tibialis Posterior Syndrome: Causes, Symptoms and Treatment

Pain on the inside of your ankle or foot can have a number of causes, but one condition that is often overlooked is tibialis posterior syndrome.

The tibialis posterior is an important muscle and tendon that runs along the back of the lower leg and passes behind the inside of the ankle before attaching to several bones within the foot. It plays an important role in supporting the arch of the foot, controlling foot movement and helping to stabilise the ankle when you walk, run or stand.

When the tibialis posterior tendon becomes overloaded or irritated, it can cause pain and reduced function. In more persistent cases, the tendon may become progressively weaker, potentially contributing to changes in the shape and mechanics of the foot.

What is tibialis posterior syndrome?

Tibialis posterior syndrome describes problems involving the tibialis posterior muscle and, particularly, its tendon.

The condition is often associated with repetitive loading rather than a single traumatic injury. It can develop when the demands placed on the tendon repeatedly exceed its capacity to adapt and recover.

It is sometimes referred to as posterior tibial tendon dysfunction (PTTD) or progressive collapsing foot deformity (PCFD) when there is significant tendon dysfunction accompanied by changes in foot alignment.

The condition exists on a spectrum. Some people experience relatively mild tendon pain while others develop significant weakness and progressive flattening of the medial arch.

Where does tibialis posterior pain occur?

Pain is typically felt around the inside of the ankle, particularly behind or below the medial malleolus — the bony prominence on the inside of the ankle.

Symptoms can also extend along the inside of the foot towards the arch.

Common symptoms include:

• Pain or tenderness behind the inside of the ankle

• Pain along the arch of the foot

• Swelling around the medial ankle

• Weakness when pushing off the ground

• Difficulty standing on one leg

• Pain when walking or running

• Increasing fatigue in the foot or ankle

• A feeling that the foot is becoming less stable

• Changes in the shape of the foot or a progressively flatter arch

Some people notice that their symptoms are worse after prolonged walking, running or standing rather than immediately during activity.

What does the tibialis posterior muscle do?

The tibialis posterior is one of the deep muscles of the posterior compartment of the lower leg.

Its tendon passes behind the medial malleolus and contributes significantly to the dynamic support of the medial longitudinal arch.

Its functions include:

• Inversion of the foot

• Plantarflexion of the ankle

• Supporting the medial longitudinal arch

• Helping control pronation of the foot

• Contributing to stability during walking and running

During walking, the tibialis posterior helps control the movement of the foot as it accepts load and subsequently assists with creating a more rigid lever during push-off.

This means that problems with the tendon can affect more than just the ankle — they can influence the mechanics of the entire lower limb.

What causes tibialis posterior syndrome?

There is rarely one single cause.

Instead, tibialis posterior problems commonly develop through a combination of repetitive loading, reduced tendon capacity and biomechanical factors.

Potential contributing factors include:

Increased activity

A sudden increase in walking, running, hiking or sporting activity can place additional demands on the tendon.

For example, increasing running mileage rapidly or returning to sport after a period of inactivity may exceed the tendon’s current capacity.

Foot mechanics

Excessive or poorly controlled pronation may increase the demand placed on the tibialis posterior as it works to control movement of the foot.

However, foot posture alone does not necessarily mean that someone will develop tibialis posterior syndrome. It is better considered as one potential factor within the overall loading picture.

Reduced calf or lower-limb strength

Weakness within the calf and lower-limb musculature may increase the relative workload placed on the tibialis posterior during walking and running.

Age-related changes

Tendons naturally undergo structural changes with age, and the tibialis posterior tendon can become less capable of tolerating high or repetitive loads.

This is one reason the condition is more commonly seen in middle-aged and older adults.

Previous injury

Previous ankle or foot injuries can alter loading patterns and may contribute to increased stress on the tendon.

Who is more likely to develop it?

Tibialis posterior syndrome can affect active people as well as those who are relatively sedentary.

Factors associated with increased risk include:

• Increasing physical activity rapidly

• Repetitive walking or running

• Obesity or increased body mass

• Diabetes and other metabolic conditions

• Previous foot or ankle problems

• Increasing age

• Reduced calf strength

• Certain inflammatory or systemic conditions

Importantly, having one of these factors does not mean that someone will necessarily develop the condition.

How is tibialis posterior syndrome diagnosed?

Diagnosis is usually based on a combination of history and physical examination.

A clinician may assess:

• The location and behaviour of your pain

• Foot posture and arch height

• Walking and running mechanics

• Ankle and foot range of movement

• Calf strength

• Tibialis posterior strength

• Single-leg balance

• The ability to perform a single-leg heel raise

• Tenderness and swelling around the tendon

One particularly useful functional test is the single-leg heel raise.

A healthy tibialis posterior tendon should contribute to the ability to rise onto the ball of the foot while maintaining appropriate control of the heel and foot. Difficulty performing this movement, particularly when accompanied by pain or weakness, can indicate significant tibialis posterior dysfunction.

Do you need an MRI or ultrasound?

Not necessarily.

Many cases can be diagnosed clinically without imaging.

Ultrasound or MRI may be considered when the diagnosis is uncertain, symptoms are persistent or severe, or when a clinician needs to assess the extent of tendon pathology.

Imaging can demonstrate changes within the tendon, but imaging findings should always be interpreted alongside the person's symptoms and physical examination.

A tendon can appear abnormal on imaging without necessarily being the primary source of someone's pain.

Treatment for tibialis posterior syndrome

Treatment depends on the severity and stage of the condition.

For many people, the main objective is to gradually restore the tendon’s capacity to tolerate load.

1. Managing activity

The first step is often modifying activities that significantly aggravate symptoms.

This does not necessarily mean complete rest.

In many cases, reducing the volume or intensity of aggravating activities while maintaining tolerable movement is more useful than stopping all activity.

For example, temporarily reducing running mileage while continuing with appropriately dosed walking, cycling or strength training may allow the tendon to settle while maintaining general fitness.

2. Strengthening exercises

Progressive strengthening is an important component of rehabilitation.

Exercises may initially include:

• Calf raises

• Resisted inversion

• Foot and ankle strengthening

• Balance exercises

• Isometric exercises

As strength improves, rehabilitation can progress towards more demanding exercises such as:

• Single-leg calf raises

• Loaded calf raises

• Single-leg balance and control exercises

• Hopping and plyometric exercises

• Running-specific strengthening

The precise exercises should be matched to the person's symptoms, strength and functional goals.

3. Addressing the whole lower limb

The tibialis posterior does not work in isolation.

A rehabilitation programme may therefore include strengthening of the:

• Calf

• Quadriceps

• Hamstrings

• Gluteal muscles

• Intrinsic foot muscles

Improving strength and control throughout the lower limb can help distribute load more effectively during movement.

4. Footwear and orthoses

Appropriate footwear can sometimes reduce symptoms by providing additional support and controlling excessive movement of the foot.

Some people may benefit from temporary or longer-term orthotic support.

Orthoses are not necessarily required for everyone, however, and they should ideally form part of a broader management strategy rather than being viewed as a cure in isolation.

5. Manual therapy

Hands-on treatment may be useful for managing associated stiffness or discomfort in the ankle, foot and surrounding tissues.

For example, treatment may address restrictions in ankle dorsiflexion or mobility elsewhere in the lower limb.

However, manual therapy generally works best when combined with an appropriate progressive exercise programme rather than being used as the sole treatment.

How long does tibialis posterior syndrome take to recover?

Recovery time varies considerably.

Milder cases may improve over several weeks, while more established tendon problems can take several months to rehabilitate.

Tendons respond to progressive loading over time, so rehabilitation is usually a gradual process rather than a quick fix.

The goal is not simply to make the pain disappear. A successful rehabilitation programme should also improve the tendon’s capacity to tolerate the activities that are important to you.

Can you keep exercising?

Often, yes — but the type and amount of exercise may need to change temporarily.

A useful approach is to monitor how symptoms respond during and after activity.

An exercise that causes a small amount of discomfort does not automatically mean that damage is occurring. However, a substantial increase in pain, swelling or loss of function may indicate that the current training load is too high.

Your clinician can help establish an appropriate level of loading and progress it over time.

When should you seek professional advice?

It is worth having your foot or ankle assessed if:

• Pain persists despite reducing aggravating activity

• You have noticeable swelling around the inside of the ankle

• You are struggling to perform a single-leg heel raise

• Your arch appears to be changing or flattening

• Your foot is becoming increasingly painful or unstable

• Walking or normal daily activities are becoming difficult

• Symptoms continue to worsen despite self-management

Early assessment can be particularly useful when there is progressive weakness or a noticeable change in foot shape.

The bottom line

Tibialis posterior syndrome is a common cause of pain around the inside of the ankle and arch of the foot. It usually develops through a combination of repetitive loading and reduced tendon capacity, rather than from one isolated event.

The good news is that many cases can be managed successfully with appropriate load modification, progressive strengthening and attention to the mechanics and function of the whole lower limb.

If you have persistent medial ankle or arch pain, particularly if you are developing weakness or changes in your foot shape, an assessment can help determine whether the tibialis posterior tendon is involved and guide an appropriate rehabilitation programme.