After the birth of a baby, low back pain may be related to the following reasons: First, it may be caused by the weakness of the lumbar muscles, the patient may cause the weakness of the lumbar muscles after childbirth due to a series of factors, such as the patient may be very fatigued during the birth process, long time doing the menstruation after childbirth or due to the poor physical condition of the patient at this time, followed by the atrophy and weakness of the lumbar muscles. At this time the patient is very easy to sprain in the lumbar region, the rapid degeneration of the lumbar spine, the above-mentioned pathological changes will easily lead to low back pain. Second, it may be caused by osteoporosis, postpartum patients are at high risk of osteoporosis, such patients may not eat enough or long-term breastfeeding, and then induced osteoporosis, this time may also produce symptoms of low back pain. Thirdly, it may be related to the spasm of the lumbar muscles. Patients may keep a certain posture fixed for a long time after giving birth, such as prolonged breastfeeding causing spasm of the lumbar muscles, which may lead to lumbago.