The way in which the foot functions or works will have a significant impact on the rest of the body. The foot is widely considered as the foundation of the body and just like the tall building analogy, if that foundation isn't correct, then something can go wrong higher up. There are numerous types of dysfunctional conditions that will affect that platform and how the feet interact with the ground. That interaction will have different affects higher up the body.
Among the issues that may go wrong is something that is commonly called “overpronation”. This phrase is frequently used and misused, so should probably be avoided. The term refers to the foot rolling inwards at the rearfoot and the arch of the foot flattening. This is actually quite a normal movement and is only a problem if there to an excessive amount of it. The reason why the term is such a problem is that there is no consensus about what is too much and what is actually normal. This leads to lots of confusion in research and in clinical practice, particularly when choices have to be made if the overpronation ought to be taken care of or not.
The impact that overpronation can have on the body are believed to vary from bunions and heel spurs in the feet to lower leg and knee joint problems in runners. There are several ways to treat overpronation, again with a lot of disagreement between medical experts as to the best way to manage it. Rationally the treatment of the overpronation ought to be directed at the cause and there isn't any such thing as a one size fits all. When the problem is due to tight calf muscles, then stretching out of those tight muscles would be the logical method. When the issue is the control of muscles at the hip, then the therapy should be geared towards that. If the condition is as a result of weak foot muscles, then that's the best place to begin the rehabilitation with exercises. If the concern is because of a bony alignment issue in the foot, then foot supports are often prescribed.