For babies with short and long legs, i.e. babies with unequal legs, parents can let their babies lie flat on the bed, straighten their legs and then observe whether the lower limbs are equal in length. The difference between the baby’s long and short legs may not be significant, so to improve accuracy, parents can remove the baby’s clothing, let the baby lie on a flat wooden board, with the legs naturally together and the lower limbs straightened, and then use a ruler to compare the baby’s heels to see if they are on the same level. Parents can also let the baby also lie flat, bend the knee 90 degrees, legs together, and then observe whether the height of the knees on both sides is at the same level. In addition, we can also observe and compare the skin lines on the inside of the thighs, which are normally symmetrical and equal on both sides.