The hazards of long and short legs are mainly the following: 1, can cause pelvic tilt, serious strain on the muscles around the pelvis, and painful symptoms, can also cause lumbar scoliosis, the patient will have lumbar pain and lumbar spine activity restrictions, a longer history of disease can also cause lumbar disc herniation, and secondary lumbar spinal stenosis, the nerve will cause long-term compression, thus causing lower limb muscle atrophy, weakness and sensory loss. 2, for the lower limb joints, such as the hip, knee and ankle joints, also have serious harm, will lead to serious degenerative changes in the above joints, joint weight imbalance, joint cartilage damage will gradually increase. It can lead to serious degenerative changes in the joints, unbalanced joint loading, and gradually aggravate joint cartilage damage, resulting in joint pain, limited joint movement, and even joint deformity. Therefore, long and short legs are more harmful to human body and should be treated early to correct long and short legs and prevent serious sequelae.