As a podiatrist I see alot of kids with 'flat feet'. We tend to look at the mechanics of the whole lower limb thwn just the foot. Internally rotated hip positions and genu valgum - which are normal at certain ages - can effect the foot position. Orthotics can be used to alter foot function but as with all conditions it is better to treat the cause not just treat what we see. I certainly wouldn't refer a kid to see an orthotist.