Babies with O-legs tend to walk in an outward-facing position and tend to waddle, presenting a duck gait. When babies walk with O-shaped legs, their feet are split outward, presenting an outward-facing gait. When walking, the legs will exert force to the outside, which will increase the muscles on the outside of the bones and decrease the muscles on the inside, and the outer contour line of the lower limbs will be shifted outward, which will be manifested as a wide crotch and curved calves. Moreover, the legs will look particularly short when viewed from the front, showing a disproportion between the upper and lower limbs. O-shaped legs of the baby, the weight of the body are often concentrated in the inner knee joints, in walking is not easy to maintain balance, prone to the phenomenon of wobbling, showing duck gait. General 1 year old baby, due to physiological development reasons, can be presented O-shaped legs, if the baby is older, there are still O-shaped legs performance, it is recommended to children’s health care in a timely manner to the Department of Health, improve the hip ultrasound, knee X-ray and other related examinations, in accordance with the doctor’s instructions to be targeted treatment.