When trying to determine foot function there are a lot of measurements that clinicians can use. The most common one of these is what we called the navicular drop. This is measure of how much the navicular bone moves from when the foot is in its neutral position to its relaxed position. This is a measure of how much the arch of the foot drops or falls. Noticeably, if this amount is a lot, then the foot is flat and probably needs supporting. Most clinicians do not measure this and just observe it, relying on clinical experience. The measurement is done a lot in research on foot function and foot orthotics.