Calf bending can be corrected, and the methods of correction are different for different age groups, as follows: 1, children within one year of age: because of knee inversion or knee ectropion caused by bending of the calf, can be corrected by manipulation. By applying inward turning force or outward turning force to the knee joint to correct the bending of the calf, the ligaments on the contracted side can be pulled, so as to achieve the corrective effect. 2, children over one year old: if the children are over one year old, they can wear lower limb braces to correct the problem. 3, young and strong adults: if young and strong adults suffer from inversion or eversion of the knee, they can be corrected through the osteotomy of the distal end of the femur or proximal tibia. 4, old people: if the knee inversion or eversion occurs, it can be corrected by osteotomy of the distal end of the femur or proximal end of the tibia. Elderly people: If the elderly people have knee inversion or eversion due to joint degeneration, they can be corrected by total knee replacement.