Flat foot is a condition where the arches on the inside of your feet are flattened which causes the sole of the foot to touch the floor when standing upright. It is likely for flat feet to be caused by the arches not fully developing during childhood and is considered a very common and painless condition. On the other hand, flat feet can occur after an injury or from the normal aging process.
While it is common not to experience any pain or symptoms of flat feet, some people do tend to sense pain in the heel or arch area. Physical activity can irritate the area and inflame the foot along the inside of the ankle. This can be caused by the tendon that is supporting the arch being stretched as it is depreciating.