Posterior Tibial Tendon Dysfunction: When Inner Ankle Pain Flattens Your Arch

Does the inside of your ankle ache after a long walk, a day on the trail or a few flights of stairs? Have you noticed that one arch looks lower than it used to? Those two things together can point to a problem with the posterior tibial tendon.

Posterior tibial tendon dysfunction, often shortened to PTTD, is the most common cause of a flatfoot that develops in adulthood.^1,4 It tends to get worse over time if it isn't treated.¹ Here's what it is, what it feels like, what you can do at home, and when to have it checked.

What Does the Posterior Tibial Tendon Do?

The posterior tibial tendon connects a muscle in your calf to bones in your foot. It runs down the inside of your lower leg, behind the bump on the inside of your ankle.^2,4 Its main job is to help hold up your arch.^1,2 The American College of Foot and Ankle Surgeons (ACFAS) calls it "one of the major supporting structures of the foot."¹

Each time you take a step, this tendon helps steady your heel and keep your foot from rolling in too far.³ When the tendon is irritated, weakened or torn, it can't support the arch as well. Over time the arch can sag and the foot flattens.^1,2

You may also hear this condition called adult-acquired flatfoot. Some specialists now use a newer name, progressive collapsing foot deformity. The new name reflects that other ligaments and joints in the foot and ankle are involved too, not just the tendon.⁴

What Causes It?

Overuse is the most common cause.^1,2 Repeated strain can create tiny tears in the tendon that take a long time to heal.² ACFAS notes that symptoms often show up after activities that load the tendon, like walking, running, hiking or climbing stairs.¹ A sudden injury, such as a fall or a sports injury, can also start the problem.²

Things that may raise your risk include:

• Extra body weight^2,4
• Diabetes or high blood pressure⁴
• Corticosteroid injections⁴
• Arthritis, including rheumatoid arthritis^2,4
• A past foot or ankle injury or surgery^2,4
• Flat feet or other foot shape differences you already have²
• High-impact sports, over-training, or long hours standing without supportive shoes²

It is not rare. One estimate from the United Kingdom puts the rate at more than 3% of women over 40.⁴

What Does PTTD Feel Like?

PTTD usually affects one foot, though it can happen in both.¹ Symptoms tend to change as it progresses. ACFAS describes a typical pattern:¹

• Early on: pain on the inside of the foot and ankle, along the path of the tendon. The area may be swollen, red and warm.
• As the arch starts to drop: the inside of the foot and ankle may still hurt. The foot and toes begin to point outward, and the ankle rolls inward.
• In later stages: the arch flattens more. Pain may move to the outside of the foot, below the ankle. Arthritis often develops in the foot or ankle.

You may also feel weak when you push off to take a step.² Pain is often worse when you walk, run or climb stairs.²

Flat feet aren't always caused by PTTD, and most people with flat feet don't have symptoms that lead them to seek care.³ If you have flat feet, our article on managing foot pain from flat feet may help.

How Is It Diagnosed?

A foot and ankle provider will usually start with a physical exam. They'll look for swelling and tenderness along the tendon.^2,4 Two simple tests are common:

• The single-leg heel rise. You stand on one foot and rise up onto your toes. Trouble doing this, or doing it without the heel turning in normally, can point to a problem with the tendon.⁴ In early stages, a person may manage one heel rise but struggle to repeat it several times.³
• The "too many toes" sign. The provider looks at your feet from behind. If they can see more than your little toe and part of the next one on the outside of your foot, that's a sign the foot is turning outward.⁴

Imaging such as X-rays or ultrasound may be used to look at the tendon and the bones of the foot.²

What Can I Do at Home?

For mild, early symptoms, Cleveland Clinic suggests rest, ice and over-the-counter anti-inflammatory medicine.² Check with your doctor or pharmacist before taking these medicines if you have other health conditions or take other medications. A few other steps may help:

• Ease off what hurts. Give the tendon a break from long walks, hikes, running and lots of stairs while it's sore.^1,2
• Wear supportive shoes. Supportive footwear, especially for activities that are hard on your feet, is one of the prevention steps Cleveland Clinic recommends.²
• Don't ignore early soreness. Getting a sore tendon checked early, before it gets worse, is also recommended.²

Because PTTD can get worse over time, ACFAS stresses that early treatment matters.¹

How Do Podiatrists Treat PTTD?

Most treatment plans start without surgery. Depending on the stage, options described by ACFAS, Cleveland Clinic and medical reviews include:^1,2,3,4

• Immobilization in a walking boot or cast for a period of time, to let the tendon rest
• Orthotics (shoe inserts) or an ankle brace to support the arch and take stress off the tendon
• Physical therapy, including exercises to strengthen the tendon
• Anti-inflammatory medicine to ease pain and swelling
• Shoe changes to give the foot more support

Recovery takes patience. Cleveland Clinic notes a short-lived flare may settle in a few weeks, while a long-standing problem can take three or four months of treatment.²

Surgery may be considered when PTTD is advanced, or when it hasn't improved after several months of nonsurgical care.^1,2 A podiatrist can explain which options fit your foot and your stage. Learn more about how we approach ankle pain.

When Should I See a Podiatrist?

Cleveland Clinic advises getting care if tendon soreness doesn't go away or your symptoms get worse.² Have it checked if you notice:

• Pain or swelling on the inside of your ankle that keeps coming back
• One arch that looks flatter than the other, or a foot that seems to be changing shape
• Trouble rising up onto your toes on one foot
• Pain that has moved to the outside of your foot

If you have sudden, severe pain, can't put weight on your foot, or have diabetes and notice a foot that is red, hot or swollen, don't wait or use the web form. Call us: Butte & Anaconda (406) 782-2278, Bozeman, Ennis & Harlowton (406) 587-8478. For a medical emergency, go to the nearest emergency room.

The Bottom Line

The posterior tibial tendon helps hold up your arch. When it's strained or worn down, you may feel pain on the inside of your ankle, and your arch may slowly drop. PTTD tends to get worse without treatment, so early care matters. Rest, ice and supportive shoes may help mild symptoms, but a sagging arch or pain that won't settle is worth a visit.

If inner ankle pain is slowing you down, our podiatrists can take a look. Request an appointment and our team will follow up within one business day. You can also find your nearest office on our locations page.

This article is for general education and isn't a substitute for medical advice. Talk with a podiatrist or your doctor about your own symptoms.

Sources

1. Posterior Tibial Tendon Dysfunction (PTTD). American College of Foot and Ankle Surgeons (FootHealthFacts.org). www.foothealthfacts.org
2. Posterior Tibial Tendonitis, Tendinosis & Tendon Dysfunction. Cleveland Clinic. my.clevelandclinic.org
3. Ling SK, Lui TH. Posterior Tibial Tendon Dysfunction: An Overview. The Open Orthopaedics Journal, 2017. PubMed Central, U.S. National Library of Medicine. pmc.ncbi.nlm.nih.gov
4. Progressive Collapsing Foot Deformity. StatPearls, NCBI Bookshelf, U.S. National Library of Medicine. www.ncbi.nlm.nih.gov