O-legs are also known as entropion of the knee. Entropion of the knee may affect the height to a certain extent, and in serious cases, it may also cause deformity of the bones of the lower limbs, which in turn may be manifested by a lowering of the height. The main causes include physiological curvature, skeletal dysplasia, trauma, infection, etc. Physiological curvature usually corrects itself with age and usually does not affect the patient’s height, but the inversion of the knee caused by other factors may change the normal force structure of the patient’s lower limbs and make the patient’s height look lower. Patients with inversion of the knee should be detected and treated in time, and the appropriate treatment method should be chosen by the doctor after examining the patient, and the patient should not blindly self-correct, so as not to cause damage to the body.