MayoClinic.com states that infants have flat feet and most will develop arches as adults, but not all do. The clinic states that flat arches may not cause physical pain for many people. Each foot has 26 bones, 33 joints and more than 100 muscles, tendons and ligaments. Given that, flat feet may result from ill-fitting shoes or a fallen posterior tibial ligament.
Walk in Wet Sand
Walk barefooted through wet sand at the beach. Examine your footprints closely. If you see that each footprint is “full,” meaning your entire foot has left an impression on the sand, you are flat-footed. If you notice your footprints show a “cut out” where your arch did not press into the wet sand, you are not really flat-footed.
Sit on a chair and cross your bare right foot over your left thigh. Flex your right foot and look at your instep. If you can see a deep, unmistakable curve along your arch bed, you are not flat-footed. If you notice that your arched foot remains flat along the medial arch, you are probably flat-footed.
Step with bare feet onto a memory foam cushion that you can buy as a scrap from mattress stores. Step off the cushion immediately and see if your footprint is full — displaying no real arch, meaning you are flat-footed, or if you see a “reverse C” shape — meaning you do have an arch.