There are usually two reasons for leg pain and back pain after pregnancy: First, after pregnancy, due to the greater weight, resulting in the waist and the legs to bear more weight, after a long time can cause the waist muscles, leg muscles and soft tissues to appear strain, strain will form aseptic inflammation foci, inflammatory metabolites will stimulate the peripheral nerves around, resulting in pain. In addition, due to fatigue, the muscles will be relatively tense, which will also aggravate the strain. Secondly, the increased abdominal pressure and weight gain after pregnancy will lead to further aggravation of the extrusion of the intervertebral disc, resulting in accelerated disc degeneration. If there is degeneration and cracks in the intervertebral discs, they may herniate when bending over and when abdominal pressure increases, and the herniation will compress the nerve roots in the lumbar region, leading to localized inflammatory edema of the nerve roots, and resulting in obvious pain in the lumbar region. In addition, nerve root compression can lead to radiating pain and numbness in the lower limbs, as well as low back pain and leg pain.