Flat foot is quite a common condition of the foot, but most of the time simply having a lower arch or flatter foot is not always a problem. What is a concern is if it is progressive and becomes painful, then it is known as posterior tibial tendon dysfunction or adult acquired flatfoot. In such cases the arch of the foot becomes steadily flatter and the rearfoot rolls inwards. This is usually followed by pain in the arch of the foot and in the ankle region. Those with this also find walking is a lot more difficult and walking uses a lot of energy resulting in lots of tiredness.The reason for posterior tibial tendon dysfunction is not fully understood, but it is a problem where the posterior tibial tendon and muscle can't just do the job that it is designed for. The principal role of the posterior tibial tendon is to hold up the arch of the foot and stop the rearfoot rolling inwards. For reasons unknown the muscle and tendon unit can't just do that job any more, resulting in the progressive nature of this disorder.
The management of posterior tibial tendon dysfunction is sort of urgent and really should be addressed as soon as it possibly can. This is because the disorder is progressive and it will get to a point where conservative measures are unsuccessful and surgery is the only alternative. As you move the surgical outcomes are typically satisfactory, they do include the fusion of some joints to prevent the disorder getting worse, that comes with some long term restrictions on gait and function, so is best avoided. In order to avoid the surgical treatment, treatment options ought to be started early. This will likely involve foot orthotics that are very supportive and angle the foot back in the correct position. Exercises are also suggested, but should not be used instead of foot supports, as they are vital to stop the flat foot from progressing.