The common causes of two feet one high and one low when walking are ischemic necrosis of the femoral head, scoliosis, deformity, and osteoarthritis of the knee joint, as follows: First, ischemic necrosis of the femoral head: when the lesion develops to a certain extent, the femoral head will collapse, and after the femoral head collapses, there will be a significant shortening of the lower extremity on that side, so there will be clinical symptoms of one high and one low when walking. Second, scoliosis and deformity: when the scoliosis exceeds 15 degrees, the patient’s lower extremities will be asymmetrical, and there may be a high and a low phenomenon when walking, accompanied by lumbar and back pain, and the diagnosis can be confirmed by taking a frontal and lateral X-ray of the spine. Third, osteoarthritis of the knee joint: osteoarthritis of the knee joint causes the knee joint to be unable to be fully straightened, and such patients will also have the clinical performance of walking with one high and one low foot, accompanied by knee pain and limited knee movement.