Correction of O-leg effective action: first stretch the external hip rotation muscle lying flat, one foot straight and flat, the other foot straight backwards to the opposite side, head and foot turned in the opposite direction, stay about 15-20 seconds, 10 times each, if the muscle is more tense, you can first bend the action knee to relax. Secondly, deep squat standing, toes facing the front of the middle of the knee ball, bend the hip and knee joint to maintain 10-20 seconds, repeat 10 times. Finally, exercise the hip adductors sitting position, feet open and sit bones the same width, the middle of the knee ball or pillow to maintain 5 minutes, repeat 3-5 times the above action to effectively improve the problem of O-leg.