Severe lateral wear of shoes may be caused by physiological factors such as bad habits, or it may be caused by ankle inversion, osteoarthritis and other reasons. 1. Physiological factors: due to the shoes do not fit the feet, personal walking habits or different points of force, can lead to different degrees of shoe wear, correct the walking habits and points of force, wear comfortable shoes, can gradually improve the phenomenon of shoes outside wear. 2. Ankle inversion: when the ligaments on the inner side of the ankle are damaged, it may cause slight inversion of the ankle joint, and if it is not treated or improved for a long time, it may lead to serious wear and tear on the outer side of the shoes. 3. Osteoarthritis: degenerative knee joint lesions can lead to osteoarthritis, wear and tear of the knee cartilage, due to knee pain or weakness, out of the protective action, can lead to changes in the pressure point of the foot when walking, serious wear and tear on the outside of the shoes. When the phenomenon of severe wear and tear on the outside of the shoes, it is recommended that the patient go to the hospital in time for examination, to clarify the cause of the disease and then give targeted treatment.