The way that the feet function or works can have a substantial impact on the rest of the body. The foot is commonly considered as the foundation of the body and just like the tall building analogy, if that platform is not right, then something might go wrong above. There are many different types of dysfunctional conditions that will affect that platform and how the foot interacts with the surface. That connection will have numerous affects higher up the body.
Among the issues that can go wrong is something that is widely given the name “overpronation”. This phrase is frequently used and abused, so should probably not be used. The term refers to the foot rolling inwards at the ankle joint as well as the mid-foot (arch) of the foot collapsing. This is quite a normal movement and is only a problem if there to too much of it. Why the word is such an issue is that there is no understanding as to what is too much and what is normal. This leads to lots of confusion in research as well as in clinical practice, especially when choices have to be made if the overpronation needs to be taken care of or not.
The impact that overpronation may have on the body are claimed to vary from bunions and plantar fasciitis in the foot to lower leg and knee conditions in runners. There are various ways to treat it, again with a lot of disagreement among medical experts as to the best way to treat it. Rationally the treatment of the overpronation ought to be directed at the cause and there is no such thing as a one size fits all. When the problem is caused by tight calf muscles, then stretching out of those muscles would be the rational approach. When the problem is the control of muscles at the hip, then the therapy really should be aimed at that. If the problem is due to weak foot muscles, then that's the best place to begin the rehabilitation with exercises. If the problem is due to a bony alignment issue in the foot, then foot orthotics will often be used.