Flexible Flat Foot
Flexible flat foot is the most common type. The arches in your feet appear only when you lift them off the ground, and your soles touch the ground fully when you place your feet on the ground.
This type starts in childhood and usually doesn’t cause pain.
Short Achilles Tendon
Your Achilles tendon connects your heel bone to your calf muscle. If it’s too short, you might experience pain when walking and running. This condition causes the heel to lift prematurely when you’re walking or running.
Posterior Tibial Tendon Dysfunction
This type of flat foot is acquired in adulthood when the tendon that connects your calf muscle to the inside of your ankle is injured, swollen, or torn. If your arch doesn’t receive the support it needs, you’ll have pain on the inside of your foot and ankle, as well as on the outside of the ankle. Depending on the cause, you might have the condition in one or both feet.