A 15-year-old boy went for an X-ray because of back pain, but found a crack in the sacral spine, saying it was an invisible sacral fracture, and both he and his parents were very worried and determined that this was the cause of his back pain. The words “invisible sacral fracture” sound scary, but in fact it is very common, it is also known as occult sacral fracture, spina bifida, it occurs mainly in the sacral spine, very few occur in the 5th lumbar spine. It is a congenital defect that is the result of a combination of genetic and environmental factors. For example, a folic acid deficiency in a woman’s body early in pregnancy may induce spina bifida. Spina bifida is caused by the failure to fuse the two vertebral arches (which should normally heal within 10 years of age) and partial or complete loss of the vertebral plate, resulting in varying degrees of clefting of the spinous process, or an open-ended deformity, or absence, or freeing. The fissure is usually filled by fibrous tissue and may also be accompanied by fibrolipoma. At first glance, it sounds very scary, but is it really? Actually, the effects of spina bifida are much less than one might think. Why? First of all, it is important to know that the upper body, which supports and stabilizes the body, is mainly carried by the spine, while the muscles of the lower back and abdomen also play a supporting role. The entire spine has anterior longitudinal ligament, intervertebral disc, posterior longitudinal ligament, synovial joint, ligamentum flavum, interspinous and supraspinous ligaments in order, of which the intervertebral disc and synovial joint account for at least 70% of the role. Therefore, less than one-tenth of the effect on stability is due to the presence of the sacral fissure. However, statistics show that among patients with chronic low back pain or who are often prone to back sprains, nearly 80% have spina bifida, which is 2-3 times higher than the incidence in the general population, indicating that it does have some effect on the production of low back pain. This is because the sacrum and the spinous process of the lumbar spine are the attachment points for the muscles of the back. This muscle is the most powerful spinal extensor muscle in the human trunk and is located on both sides of the spine in the low back, from the sacrum to the occiput. When both sides contract at the same time, it causes the spine to extend backward, such as head lifting and chest raising movements; when one side contracts, it causes the trunk to flex to the same side. Due to the presence of the cleft, the free or non-healing of the spinous process allows the aforementioned muscles to attach to the free spinous process or fibrous tissue, while lacking a solid bony attachment point. From a mechanical point of view, this inevitably prevents its contractile function from functioning properly and results in easy fatigue of the lumbosacral muscles, muscle weakness, and out-of-shape movements. Therefore, for some people who have spina bifida and need to use their lumbar strength frequently, they will be more likely to sprain or develop back pain than normal people. So do people with spina bifida need treatment? For people who do not have symptoms, no treatment is needed, but there are still some things that need to be paid more attention to than normal people. First of all, it is recommended that these people do not engage in jobs that often use back force, such as porters, dancers, etc., avoid participating in strenuous sports, such as basketball, soccer, etc., avoid sitting and bending over to lift heavy objects in daily life and work, and should squat and hold up when they do need to lift heavy objects. For patients with spina bifida who already have chronic low back pain, the first step is to go to a specialist to clarify the cause of the low back pain and to rule out any other problems besides occult sacral bifida, such as the presence of combined intravertebral tumors or disc herniation, etc. If necessary, a lumbar magnetic resonance imaging (MRI) examination should be performed. After excluding other causes, only then can the treatment be targeted. The treatment method is the same as the treatment of common lumbar strain, there is no need to do any surgery to repair the fissure, usually physical therapy, massage, internal Chinese and Western medicine and other methods can be. At the same time, daily rehabilitation and health care is very important, to avoid sedentary and bending, more bed rest, preferably on a hard mattress, strengthen the lumbar back muscle exercise, appropriate exercise, of course, it is best to swim. And for some people who must often sit, they can wear a lumbar girth to reduce the burden on the lumbar spine.