When someone has flat feet, it means their feet have little arch or no arch at all. When someone has a normal arch, you’ll see a curve along the inside of the foot in the area between the ball of the foot and the heel. The arch of the foot usually forms during childhood but in some cases, the arch fails to form. In other cases, a normal arch forms but then the feet become flat later in life due to age, an injury or other contributing factors.
There are two main types of flat feet: flexible and rigid.
Most people with flat feet have the flexible type. This means they have an arch when there’s no pressure applied to the feet, such as when they’re in a seated position. However, when they stand or put pressure on the feet, the arch is no longer visible.
Rigid flat feet is less common. This is where there is no visible arch present at any time, even when there is no pressure applied to the feet.
Many people with flat feet never experience any symptoms at all and the condition doesn’t prevent them from leading a full, active life. In other cases, people with flat feet may be more susceptible to experiencing pain, fatigue and swelling in the feet as well as other areas of the body such as the knees and lower back.