What is Adult Acquired Flatfoot (Posterior Tibial Tendon Dysfunction)?  

There are a number of causes of Adult Acquired Flatfoot, a condition categorised by a drop in the arch of the foot and causing the ankle to roll in and the foot to point outwards.  One of the main symptoms of the condition is pain down the tendon on the inside of the ankle, known as the Posterior Tibial Tendon.

The Posterior Tibial tendon serves as one of the major supporting structures of the foot, helping to maintain the arch. Posterior tibial tendon dysfunction (PTTD) is a condition caused by changes in the tendon, impairing its ability to support the arch. This results in flattening of the foot.

Although this condition typically occurs in only one foot, some people may develop it in both feet. PTTD is usually progressive, which means it will keep getting worse, especially if it isn’t treated early.

Causes of PTTD

Overuse of the posterior tibial tendon is often the main cause of PTTD. The symptoms usually occur after strenuous physical activities that involve the tendon, such as running, walking, hiking, or climbing stairs.

Signs and Symptoms of PTTD  

Signs and symptoms of PTTD may include pain, swelling, flattening of the arch, outward pointing of the foot and an inward rolling of the ankle. As the condition progresses, the symptoms will change.

Other symptoms include pain with activity, pain on the outside of the foot and ankle, bony lumps on the top and inner-side of the foot, and even numbness and tingling down the inner-side and under the foot if the condition causes compression on one of the major nerves.

Conservative Treatment

Because of the progressive nature of PTTD, accurate diagnosis and early treatment are very important. If treated early enough, your symptoms may resolve without the need for surgery and progression of your condition can be prevented.

Untreated PTTD could leave you with an extremely flat foot, painful arthritis in the foot and ankle, and increasing limitations on walking, running, or other daily activities.

In many cases of PTTD, treatment can begin with non-surgical approaches that may include:

  • Activity modification. An initial change to your exercise regime or daily activities may be needed to avoid the condition getting worse. The introduction of a low impact alternate activity may also be of benefits such as swimming or cycling. 
  • Strengthening. It is important that strength is addressed for this condition so that the affected tendon can tolerate more load. This is done initially with isometric loading to load up the affected area in a pain-free way. When pain has reduced a strengthening program will be incorporated for the surrounding influencing muscles. 
  • Increase in ankle range. Poor ankle range can be a common mechanism contributing to this injury, therefore intervention to increase ankle ROM will be implemented when necessary.
  • Heat or Ice.  This condition may respond better to either heat or ice. Try heat prior to exercise and Ice afterwards.
  • Anti-inflammatory. Nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen, naproxen, or aspirin, will help with pain and swelling as per GP instructions.
  • Adequate footwear. Supportive and appropriate footwear is strongly recommended to stabilise the foot and ankle. Avoid wearing thongs, slippers, sandals and barefoot.
  • Taping/Bracing. Taping or bracing can help to stabilise the foot and ankle and reduce excessive stress on the Posterior Tibial Tendon.
  • Orthotic therapy: A custom orthotic device placed in the shoe can help address possible causative factors such as flat feet, to reduce stress on the Posterior Tibial Tendon.
  • Extra Corporeal Shockwave Therapy. A non-invasive treatment where shockwaves are sent into the foot to stimulate the body’s own healing process.
  • Injection therapy. If conservative treatment is plateauing injection therapy may be considered for pain relief.
  • AlterG Anti-Gravity Treadmill. Continuation of training on the AlterG to decrease the load on the foot and its surrounding muscles whilst maintaining an exercise program.


In cases where PTTD has progressed substantially or has failed to improve with non-surgical treatment, surgery may be required. For some advanced cases, surgery may be the only option.