Posterior Tibial Tendon Insufficiency vs Low Arches: How To Tell The Difference

Posterior Tibial Tendon Insufficiency vs Low Arches: How To Tell The Difference

By now you might have noticed that at The Feets, we get pretty passionate about foot health and sharing our knowledge on the subject. If you recently read our blog on Foot Pain: Is it Plantar Fasciopathy or Low Arches? and thought “Ding-ding-ding! I must have low arches!” then you may have a few more questions. Primarily: “Have I always had low arches? Or have they developed recently?”

That’s what we’re taking a closer look at here, because your foot mechanics can impact everything from the shoes you should be wearing to your long-term foot health, so understanding the how and why of your low arches can be really helpful, especially if you are a runner. 

Let’s take a look at two types of low arches, how they might affect you, how they could impact your training, how to differentiate between them, and what to do if you develop pain or other symptoms… 

What is a low arch? 

Low arches are based on navicular height, and are sometimes referred to as ‘flat feet’, ‘fallen arches’, or – the true name for flat feet – ‘pes planus’. This means your feet press flat on the ground when standing, and there is no visible arch. 

This might happen due to genetics, an injury, being overweight (which can cause the tissue in the feet to stretch), or being over the age of 65, since studies have found low arches are associated with older age.

Low arches are a common foot shape and are usually nothing to worry about unless they are causing you issues with function, stopping you from taking part in activities or training, or causing pain in your feet. Any symptoms experienced as a result of low arches are likely to be exacerbated by being overweight, applying excessive loads to the feet (more than the soft tissues can cope with), or having an abnormal gait or biomechanical pattern. 

There are different types of low arch, including:

  • Flexible – The most common type, which means you have low arches when standing only, not when sitting. With flexible low arches, the arch disappears when you apply weight. This kind of low arch develops from childhood or during adolescence. 
  • Rigid – This type means you have a low arch when standing or sitting down. It usually develops during adolescence and can become more pronounced as you age. 

The main thing you need to know about low arches is that, unless they seem to be causing you problems like pain or stiffness, then they’re probably A-OK, and you don’t need to do anything differently. 

What is posterior tibial tendon insufficiency? 

This is where low arches become somewhat of a problem. The third kind of low arch we’re focusing on in this article is adult-acquired low arches, otherwise known as posterior tibial tendon insufficiency. Posterior tibial tendon insufficiency is sometimes referred to as ‘posterior tibial tendon dysfunction’, ‘adult-acquired flat foot’, or even ‘collapsed arch’, and it’s when the arch of the foot collapses unexpectedly, causing the foot to tilt inwards in some cases. 

Symptoms of posterior tibial tendon insufficiency include: 

  • The ankle rolls inwards when standing 
  • Pain and/or swelling along the inside of the foot or ankle, which may increase when standing, walking, standing on toes, or during other activities
  • Difficulty walking on uneven surfaces, or up and down stairs 
  • A limp that gets worse over time 
  • Uneven wear on the soles of shoes

Posterior tibial tendon insufficiency is most commonly caused by high stress on the tendon, but it can also be caused by a tear (from an injury) in the posterior tibial tendon that supports the arch. All sorts of things can contribute to this tear, such as:

  • A fall
  • A high-impact sports injury, for example, when playing basketball or football 
  • Repetitive force on the tendon causing tendon degeneration, for example during running 
  • Added force due to being overweight can cause the tendon to break down faster 
  • Older age, as the tendon usually deteriorates as you age 
  • A prior ankle or foot injury can also cause the tendon to break down faster 

What’s the difference?

The main difference to note between low arches and posterior tibial tendon insufficiency is that low arches are a normal variability of the anatomy that you can live with your whole life with completely normal mobility and no pain or repercussions from having them, whereas posterior tibial tendon insufficiency is a condition caused by excessive eccentric strain on the tendon above what it can cope with. If this condition is severe, it can cause changes within the midfoot which can lead to adult-acquired flat foot deformity, and cause pain, limited mobility, or general weakness in the affected foot.

Put simply, low arches are not a cause for concern unless they are causing you pain or discomfort, while posterior tibial tendon insufficiency is likely to cause some issues either in the present or in the future. 

How do I know if it’s posterior tibial tendon insufficiency?

A podiatrist will be able to properly diagnose this condition if you have it, but you may be able to identify it by the following features:

  • Pain behind the ankle bone (medial malleolus) is a key symptom of this condition 
  • Pain where the arch of the foot should be when standing, walking, running or exercising, and when standing on toes 
  • Possible swelling along the inside of the foot
  • In more severe cases, the ankle may roll inwards when standing or walking 
  • Difficulty walking in certain areas, such as up stairs or on uneven ground
  • Usually a short-term condition that can take several months to heal
  • Typically develops after an injury (in around 50% of cases)

Can low arches affect my running training? 

When it comes to running, low arches are nothing to worry about if you have always had them, and are no cause for concern unless they are causing you pain or discomfort. Certain studies suggest low arches can lead to some overuse injuries, and that those with high arches may have improved dynamic balance and speed compared to those with low or neutral arches, however, this does not mean you need to do anything differently – low arches should not get in the way of your running ambitions. The only difference you may notice is that you require a specific type of running shoe to offer your feet the best support during training.

If you have posterior tibial tendon insufficiency, this could impact your running by causing you pain or negatively impacting your balance or gait. If this is the case for you, it’s best to visit a podiatrist who can check for the condition and make suggestions for the ideal way to continue your training without pain. 

Can low arches be treated? 

As mentioned, low arches don’t need to be treated unless they are causing issues, but there are a few things that can be done to help if you have posterior tibial tendon insufficiency that’s causing you pain or affecting your balance or gait. It’s always helpful to visit a specialist (a podiatrist is best!) who can advise on treatment options such as:

  • Temporarily resting to stop the pain from worsening, and switching to low-impact exercises like cycling or swimming to give the tendon a break 
  • Applying ice to painful areas of the foot or ankle – you can do this for up to 20 minutes 3 or 4 times a day to help ease pain 
  • Physical therapy exercises to strengthen the tendon – these exercises can be advised by a podiatrist for best results 
  • Orthotic shoe inserts to support your tendon and the arch of your foot – again these can be advised by a podiatrist who can ensure they are the best fit for your feet 
  • In extreme cases where the above methods have not helped, surgery can be arranged to address problems 

If after resting and applying ice to the affected area you do not feel any improvements in pain, speak to your doctor or a podiatrist so they can analyse your foot mechanics and provide personalised advice to help you get back to your training. This might mean suggesting wide, comfortable shoes with a low heel, orthotic insoles to support your feet, specific foot stretches and exercises, or something else. While these interventions won’t change the shape of your foot, they may help to address any pain or stiffness. 

Can posterior tibial tendon insufficiency be prevented? 

There are multiple risk factors that can cause or be a contributing factor to this condition, and it cannot be prevented entirely. You can, however, reduce your risk by always wearing supportive footwear with arch support, avoiding footwear that can increase your risk of injury (such as high heels or flip flops), and – something we love at The Feets! – doing regular preventative stretches and exercises to keep your feet healthy and active. 

A few exercises that can help with low arches include:  

  1. Arch lifts – Stand straight with your feet under your hips, keep toes on the floor, and roll your weight to the outer side of your feet, lifting your arches up as you go. Doing 10-15 repetitions of this 2 or 3 times will exercise the muscles that help to support your arches.
  2. Towel curls – Sitting down, place a towel under your feet, keep heels on the floor and curl your toes inward to scrunch the towel. Hold for a few seconds and release, and do 10-15 repetitions 2 or 3 times.
  3. Toe raises – While standing, press your big toe to the floor and lift the other four toes, then switch so your big toe is lifted and the others are pressed to the floor. Hold each lift for 5 seconds, and repeat 5-10 times on each foot. 
  4. Ankle inversions – Keeping your heel on the floor, place a resistance band around the front of your foot and wrap the other end around a heavy table leg or chair – something that won’t move and is in front of the foot, not diagonal to it. Rotate your foot inwards and upwards, feeling tension on the band. This exercise works the tibialis posterior muscle, and a good schedule for this would be doing 3 sets of 8-12 reps around 4 times a week.
  5. Seated calf raises – Sitting down holding heavy weights such as dumbbells on your knees (use your judgement of what weights will be suitable for this), lift your heels off the ground as high as possible, then slowly lower them back down. Do 3 sets of 6 reps, leaving a good amount of time between each set. Always be careful when lifting heavy weights if you are doing the exercises barefoot. 

You know we love a pre-emptive foot care routine at The Feets, and if you have low arches this can help to keep your feet happy and healthy, especially if you are a runner or athlete with big goals that require your feet to be in tip-top condition. Addressing any little niggles or injuries as early as possible is the best way to stop them from causing future pain and issues, and stop your training from being interrupted. 

Whether it’s lifelong low arches or newly-acquired posterior tibial tendon insufficiency, taking care of your feet before things like pain, stiffness and mobility issues get out of hand is the best way to ensure you can keep inching towards those big running goals.

So, whether high, neutral or low arches… go get it. 


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We’re The Feets. We know what it’s like to set the alarm for 5am, drag yourself out of a warm bed, lace up the shoes that are starting to show the miles, and head out in the grey morning to clock a few Ks before work. We’ve been there, we are there, and we’ve got your back. Follow us on Instagram for stories, motivation, tips and tricks, or just to be part of the growing community of those wanting to make something of themselves. 

Written by: Logan Estop-Hall

Mountain man. Ultra-runner. Entrepreneur. Adventure sports do-er. Obsessive reader. Happy husband, proud father and passionate about helping people find health and happiness through sport, with a specific focus on lower limb health.

Medically Reviewed By: Matt Hart

Experienced sport and MSK podiatrist with a sport & exercise science background & MSc in clinical biomechanics. Working mainly in sport with athletes and football players both professional and non professional. Specialist interest in running footwear & their influence on performance.