What is a Flat Foot?

In simple terms, a flat foot has a fallen arch and is turned outwards. There are many causes of flat feet in adults including posterior tibial tendon dysfunction (PTTD), arthritis, injury, and diabetes. PTTD is the commonest cause of adult acquired flat foot. The posterior tibial tendon runs along the inner side of the ankle and functions to support the arch. If this tendon tears the arch slowly collapses. Risk factors for PTTD include obesity, diabetes, hypertension, having flat feet as a child, and high impact sports such as soccer, tennis and basketball.

What are the Symptoms?

The symptoms vary depending on the cause of the flat foot. PTTD causes pain and swelling on the inner side of the ankle. Pain is worse with activity as well as standing for long periods. In latter stages pain may be felt on the outside of the ankle as the heel bone shifts from under the ankle bone. People with a prior injury or mid foot arthritis experience pain across the top of the foot. Spurs may impinge on nerves causing tingling and burning. Diabetics may suffer from “Charcot arthropathy” where the bones disintegrate and collapse. This is often painless as there is no sensation in the foot but can lead to deformity and pressure areas causing ulceration.

What is the Treatment?

Non-surgical options include orthotics, braces, exercises and sometimes custom footwear in the case of diabetic flat feet. 

Surgical treatment is varied and depends on the particular type of flat foot. The aim is to reduce pain and improve your function rather than necessarily provide a normal shaped foot. In diabetic Charcot feet the goal is to reduce the risk of ulceration, infection and subsequent amputation.