If XO-leg deformity is found in newborns or infants, XO-leg deformity can be corrected by using the appropriate orthopedic brace with proper diet and exercise, but using duck sit will not correct the deformity in infants or newborns. If the XO-leg deformity is discovered in adulthood or after adolescence, even if orthopedic braces are used, there is no way to achieve a good treatment effect, and the use of duck sit cannot achieve the treatment purpose. Generally, it can only be maintained temporarily, and orthopedic treatment is needed when the bones, especially the epiphyses, close in adulthood.