The correction of O-legs at the age of six includes conservative treatment and surgical treatment. 1. Conservative treatment: Some mild “O-leg” asymptomatic people may not take any treatment. For those with mild symptoms, corrective insoles and supports (e.g. orthodontic devices, splints, etc.) can be used, which are designed to relax the medial collateral ligaments of the knee joint in order to restore the stabilizing structure of the medial and lateral knee joints, so as to make the tibia bone outwardly rotate and achieve the purpose of correction. 2. Surgery: For patients with very severe “O-legs”, surgical treatment can be adopted, often by inverted U-shaped osteotomy of the tibial tuberosity. In addition to the above methods, children with O-legs can also be corrected through rehabilitation and corrective training, changing bad walking habits. It is recommended that children with O-legs go to the hospital for regular rehabilitation under the guidance of a doctor if any of the above conditions occur.