To determine whether there is flat feet can be used to contrast method, talcum powder method, X-ray film and other methods, as follows: 1, contrast method: take off shoes and socks, bare feet, check the size of the arch, and then compared with the normal arch, if the arch becomes smaller, it suggests the existence of flat feet. 2, talcum powder method: put talcum powder on the ground, and then let the patient stand barefoot on the talcum powder, talcum powder will stick to the bottom of the foot on. Then let the patient walk on a flat surface, if there is a flat foot, the patient’s plantar talcum powder all stick to the ground, in the shape of a foot. If there is no flat foot, the forefoot and heel of the patient’s foot and the lateral edge of the talcum powder is exposed on the ground, so that the comparison can determine whether there is a flat foot. 3, taking X-rays: taking lateral X-rays of the foot to determine the size of the arch, you can determine whether there is a flat foot.