Flat foot is a fairly common condition of the foot, but most of the time simply having a lower mid-foot (arch) or flatter foot is not necessarily a problem. What is a problem is if it is progressive and becomes painful, then it's known as posterior tibial tendon dysfunction or adult acquired flatfoot. In such cases the arch of the foot becomes progressively lower and the heel rolls inwards. This is usually followed by pain in the arch of the foot and in the rearfoot region. Those with this also find walking is a lot more difficult and walking consumes a lot of effort leading to a lot of tiredness.The main cause of posterior tibial tendon dysfunction is not really totally, but it is a problem in which the posterior tibial tendon and muscle can not just do the task that it is intended for. The key role of the posterior tibial tendon is to support the arch of the foot and prevent the rearfoot rolling inwards. For some reason the muscle and tendon unit can't just do their task any more, resulting in the progressive nature of this problem.
The treatment of posterior tibial tendon dysfunction is somewhat urgent and really should be addressed as early as it possibly can. The reason being the problem is progressive and it will get to a point where conventional interventions fail to work and surgery is the only option. While the surgical outcomes are in general acceptable, they do include the fusion of some joints to stop the problem getting worse, that does have some long term restrictions on gait and function, so is best avoided. In order to avoid the surgical intervention, treatment options needs to be started early. This will consist of foot supports that are very supportive and angle the foot back in the correct position. Exercises are also suggested, but should not be used rather than foot supports, as they are important to stop the flat foot from getting worse.