For a flat foot ,a good shoes is a must while exercising. Those with flat foot need a shoe that provide balance and good cushioning effect. Cross training shoes are suggested better for providing support while exercising than traditional sports shoe. Certain types available in the market are-motion control shoes. They are stable ,provides a good grip .They are the "walking shoes" .Not suitable for running as they are heavy. Good running shoes are the support shoes that are lighter but supports the flat foot. Stability shoes are good walking shoes but they are not heavy ,may give a feeling of lesser grip .