If you find that your baby’s legs are not the same length, you should go to the hospital in time. The common causes of the difference in the length of the legs are congenital hip dislocation and femoral head dysplasia. If the hip joint is dislocated, most of them can be reset by manipulation at an early stage, and if necessary, surgery should be performed; if the femoral head is dysplastic, orthotic fixation of both lower limbs can be performed at an early stage to squeeze the hip joint so that the femoral head can be fully developed, and if the disease is found after one year of age, the treatment is less effective. Of course, there are also related muscle diseases that can cause the legs to be different lengths, and electromyography and other examinations can be performed, along with different thicknesses of the legs, etc.