The way in which the feet function or works could have a significant impact on the rest of the body. The feet are generally regarded as the foundation of the body and just like the tall building analogy, if that platform isn't right, then something can go wrong higher up. There are numerous kinds of biomechanical problems that can impact that platform and how the foot interacts with the surface. That interaction will have different impacts further up the body.
One of the issues that can go wrong is something that is generally termed “overpronation”. This phrase can often be used and misused, so probably should be avoided. The term refers to the foot moving inwards at the rearfoot as well as the arch of the foot flattening. This is quite a normal movement and is only a problem if there to too much of it. The reason why the phrase is such an issue is that there is no agreement about what is too much and what is actually normal. This can lead to lots of uncertainty in research as well as in clinical practice, particularly when choices have to be made if the overpronation should be taken care of or not.
The impact that this problem can have on the body are claimed to vary from hallux valgus and heel spurs in the foot to leg and knee joint conditions in runners. There are many ways to treat it, again with a lot of disagreement between health care professionals regarding the best way to treat 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 condition is caused by tight calf muscles, then stretching out of those muscles would be the reasonable approach. If the problem is the control of muscles at the hip, then the treatment ought to be geared towards that. If the problem is caused by weak foot muscles, then that is the best place to start the rehab with exercises. If the concern is because of a bony alignment issue in the foot, then foot orthotics are often prescribed.