How flat should it be? Should it at all? Should it be limited? If so how much? Confused? Understandably so. Current research is not only unable to define what it is, but unable to agree or “Prove” that anything from ignoring it to full motion control of a flat foot is helpful.
However, it is known that one cannot walk without supination and pronation (raising and lowering of the arches respectively). It is also known that everyone is different, not only with the foot but also the rest of the body.
I am often asked “Am I flat footed?” My answer is, in most cases, it is not weather your feet are flat nor how high your arches are, but rather “How much are your feet Flattening during your activity?” The motion of flattening is what is most important.
If any part of the foot during motion is not pronating or supinating as it should be, along with being completely symmetrical in timing, trajectory and speed of motion, then you probably will end up with a problem somewhere along the kinetic chain (the foot to the back). We are essentially walking robots. Machines that move require all the above.
Some feet look like “flat feet” and some like “high arches”. The appearance is very subjective. Of course, when you see it flattening or flattened with stance, you’ll know it. Again, usually, what is most important is the action of the body during the activity.
So should “flat feet” be biomechanically treated with appropriate shoes and foot orthotics? Yes, in many cases, starting with the shoes and orthotics along with therapeutic modalities as needed with an individually tailored plan.