Posterior Tibial Tendon Dysfunction (PTTD)

This article is all about Posterior Tibial Tendon Dysfunction (PTTD). PTTD is the most common cause of a flat foot in adults, and it's also a common cause of pain around the inside of the ankle & foot. 

The information in this article is also presented in video format below.

1) What is PTTD ?

PTTD is a problem related to an important tendon called ‘tibialis posterior’ which is located on the inside of the ankle. The main job of the tibialis posterior tendon is to support the arch on the inside of the foot, also called the instep arch or medial arch. This arch has an important role in walking and running as it helps with foot flexibility, shock absorption and propulsion.

A normal medial arch is really quite a amazing structure as it allows the foot to be flexible and adapt to different ground conditions when the foot is flat on the floor and then it tightens up at the point of toe off, when the foot is propelling you forwards when waking or running. And the particular role of the tibialis posterior tendon is to lift the arch at the point of toe-off, which then locks the foot into a rigid lever ready to push you forwards. 

In PTTD the tibialis posterior tendon becomes weak and painful. In the early stages the symptoms are pain and swelling over the inside of the ankle, aggravated by walking or running. 

The painful area in PTTD

In the later stages the tendon then becomes weak and degenerative to the point that it can no longer lift the arch up properly during the walking cycle. Eventually this causes a collapse of the medial arch which can be seen as a flat foot. 

A Flat Foot

We use a few tests to check the position of the foot and the strength of the tendon. One is the ‘too many toes sign’. If you put your phone on the floor and take a picture or video of your foot position from behind when standing normally, you should be able to see the little toe and maybe the one next door. If you can see more then 2 toes then this indicates a flattened foot. 

A positive’Too Many Toes’ sign on the right foot

The second test is a single leg heel raise. If you can do this with your good foot but struggle on your affected foot due to pain and /or weakness then this might indicate a weakness of the tendon.

Single leg heel raise 

2) Why have I got PTTD ?

Well this always comes down to a single issue - overloading of the tibialis posterior tendon, which essentially boils down to doing more walk or running than your foot can cope with at the time. 

At one end of the spectrum, you might be an athlete who has pushed your running distances too quickly and overloaded the tendon, or you might be someone who has taken up running or hiking for the first time but again, you’ve increased your distances too quickly and not given enough time for your foot to adapt & strengthen. 

Or you could be someone who has changed jobs from something sedentary to something where you might be on your feet all day. Or you could be someone who isn’t used to long walks or runs but you’ve suddenly done something as a one off, like a charity event but you might not have done any training and its just been too much for your foot. Or you might be someone who has recovered from an illness where you might have been off your feet for a few months and have then been too quick to get going again. 

Whatever the reason, there will always be history of excessive walking or running in every case

There are also certain risk factors which can contribute to developing PTTD. Being overweight is the most significant of these, for obvious reasons. Also, poorly controlled diabetes or thyroid disease. Women are also more prone the condition, particularly the over 40’s for reasons we don’t fully understand but we do know that the frequent use of poorly supportive or ill fitting footwear can be a contributing factor.

3) What are treatment options ?

Reducing Load 

Well it might seem obvious but an immediate reduction in the amount of walking or running you do is the single most effective way of reducing symptoms. We know that the cause of PTTD is an overloading of the tibialis posterior tendon. Well, in order to get it better you have to reduce the load going through it. 

The tendon needs a period of relative rest in order to give it a chance to go through a healing process. But what is relative rest ? Well it usually isn't total rest from walking or running. It's a general reduction in the activities that are causing the pain. Whether that's standing, walking or running. And you have to reduce these activities to the degree where pain starts to improve. 

This will be different for different people but as a general rule, you should be reducing your weight bearing activities until the pain settles down to a mild and manageable level while doing that activity. If, despite these reductions, you still get a lot of pain while walking or running and it fails to settle down by the next day then you are still doing too much because you’re still aggravating the tendon. 

And a word specifically for runners; if you've tried reducing your distances and the pain just won't settle then it may be that you have to stop running completely for a spell. And I know you hate being told this but you won’t be doing yourself any favours by pushing aggressively through the pain. You could always substitute running with cycling and you can do pretty much anything in the gym, except the treadmill. So please be patient and hopefully your sacrifice will be rewarded further down the line. 

Now this reduction in weight bearing activities may take a bit of experimentation but it's really vital that you stop aggravating the tendon or you're going to be fighting a losing battle. A step counter or smart watch can be really helpful in giving you some feedback about how much time you are spending on your feet and you can then relate this to your symptoms in order to find out what you can manage, and more importantly what is too much for you. 

Of course, if you are overweight, then its going to be helpful in the long term if you can reduce your body weight to a healthy level. This will help to reduce load, promote healing and avoid future recurrences.

Medial Arch Support

The next important thing is to support the medial arch with some insoles. This is really important as a good insole will significantly reduce the load going through the tendon. You can buy off-the-shelf insoles such as the ones in the picture below, either online or from an outdoors store, but a key test is to squeeze the arch itself and check that its firm and doesn’t collapse. If you can collapse the arch by just squeezing it then it won’t maintain its shape with your full weight through it. The firmer the better. 

Medial Arch Support Insole (link to product)         Squeezing the arch to check firmness

A better option is to go and see a podiatrist who will provide you with a bespoke pair of insoles tailored to your individual foot posture. I say pair, because insoles always come as a pair and you should wear them in both shoes even though it’s likely that you only have symptoms in one foot. This will keep you balanced. 

Podiatrist fitting a bespoke insole

The type of footwear you put them in is also important. The best option is a hiking shoe or a trail show, or a pair of good running shoes. These tend to be more supportive that a normal sports shoe. Other options are well fitted lace up shoes. Avoid floppy fashion shoes, open healed shoes or converse type shoes. 

Good shoes for Insoles

When you get your shoe, remove the standard insole and replace it with your new one. Your foot might need a few days or weeks to get used the new position so at first, use it for just an hour or 2 a day and then slowly increase this until you are using them all the time. Otherwise you might find you get new aches and pains in your feet as well as the PTTD pain. You’re going need to need to use these insoles until the problem has got fully better, and some people choose to continue using them for the long term in order to stop the problem coming back again. 

A suitable insole supporting the medial arch


The last early treatment to consider in the use of an anti-inflammatory. Not everyone will need this treatment, but if your tendon is swollen, tender and generally angry and irritable then an anti-inflammatory can he helpful in settling this down. This can either be a gel to rub into the area or tablet like ibuprofen, both of which you can buy over the counter in most countries. Just remember that not everyone can take anti-inflammatories so please check with a pharmacist first. Use them as it says on the packet at maximum dose daily over at least 3 weeks. Taking them sporadically won’t work

Very occasionally, if the swelling doesn’t settle down within a few weeks then a cortisone injection into the tendon sheath can be helpful. This is best done under ultrasound guidance as accuracy is key to getting the best result. Of course you will need to see a specialist clinician at this stage. 

Ultrasound Guided Injection

In cases of persistent inflammation, a specialist may also recommend using something more supportive than insoles, such as a brace or an immobilisation boot to rest the tendon as much as practically possible. 

Immobilisation Brace & Boot

How long will it take ?

The whole point of what we’ve discussed so far is to reduce the pain and any swelling and therefore allow the tendon a period of rest so it can then start the healing process. We now have to be patient. How patient will be different for everyone but you need to be sure the tendon has settled right down before starting to build up the strength again. This will usually take at least 6 weeks and sometimes 3 or 4 months. Only when the swelling has fully resolved and the pain is minimal (and ideally, also fully resolved) should you then start to increase your walking levels again or take a first tentative run. And this time, you will need to be really careful to increase your distances slowly, over another 6-12 weeks. 

Over this time it can also be helpful to start doing some progressive loading exercises for the tibialis posterior tendon. This will help to slowly increase its strength and resilience and make it less likely that the problem will start up again as you increase your distances. 

The video below describes a suitable exercise programme.

And that’s pretty much it. It's slow progress and it can be frustrating, particularly for you keen runners who want to get back to running as soon as possible but it really is worth being patient and listening to your body throughout this process. Be prepared to back off and rest a bit longer if you need to. It’s really not worth being silly, pushing too hard & too fast and going back to square one.

If things fails to improve then do get checked out by a specialist clinician. There are circumstances where the tendon may have split or torn, and if you’ve had a flat foot for a long time then secondary arthritis can sometimes develop in the foot which can complicate matters and cause ongoing pain. In these cases the insoles can still help but it may be that you have to wear them for the long term in order to keep symptoms under some control. 

An X-ray can check for arthritis and an MRI or Ultrasound Scan can be helpful in checking the health of the tendon and to look for any splits or tears. A specialist will be able to advise you if surgery may be required. 


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