The biomechanics and functionality of the arch of the foot is critical to normal walking and as well as running gait and biomechanics. The support of the arch of the feet are achieved by a number of things, for example the shape of the bones, the ligaments, the muscles as well as the plantar fascia. One of several vital muscles in the dynamic stability of the arch of the feet are the posterior tibial muscle. This is a powerful muscle that is in the lower leg. The tendon of this muscle passes around the medial side of the ankle joint and attaches underneath the bones that comprise the mid-part of the arch of the foot, so this particular muscle is so important for stabilizing the mid-foot. In some people, this muscle seems to lose it capacity to support the foot, resulting in a condition known as posterior tibial tendon dysfunction or adult acquired flat foot.
This condition usually starts off with a moderate discomfort in the midfoot or medial side of the ankle joint and the mid-foot of the feet gradually collapses and the ankle joint rolls inwards. This is all due to the muscle not being able to do its job adequately. If therapy is not implemented, then the pain and disability gets worse. In its later stages it is usually very debilitating and painful. It eventually has a significant impact on quality of life and also the ability to walk. It is extremely fatiguing as a lot of energy is required to walk with Posterior Tibial Tendon Dysfunction .
Since the long term outcomes of this disorder may be so debilitating, it is important that it is caught as early as possible and treatment begun. The longer the delay the more difficult it is to deal with. During the early stages, the only adequate treatment are usually quite hard or stiff foot supports. They must be hard as the forces that are flattening the feet are so great that they need to be opposed. A less firm orthoses will do nothing. A high top hiking or basketball type shoe or sneaker can also be useful at stabilising the rearfoot. If this is not sufficient then more complicated ankle braces would be the next intervention. If this fails or the treatment is started far too late, then surgery is actually the only satisfactory intervention at this stage.