Low back pain is afraid to bend mainly for four reasons: the first case may be acute lumbar sprain, such as lifting, lifting heavy objects due to improper force, resulting in excessive force, pulling the muscle tissue of the waist, will lead to muscle fiber damage, which will lead to significant local swelling and edema formation, will stimulate the peripheral nerves pain. When bending over, it will lead to further stimulation of the lumbar muscles at the site of injury, resulting in a more pronounced pain, so that you do not dare to bend over. The second condition is due to the synovial joint of the lumbar spine becoming embedded, especially when bending over, a sharp extension of the waist may cause the synovial joint to embed the bursa and synovial membrane in it, resulting in significant pain in the lumbar area, and the pain will be more obvious when bending over. The third condition is due to the formation of a sterile inflammatory lesion in the lumbar region, especially after cold and exertion, resulting in the intensification of the inflammatory lesion, which will stimulate the peripheral nerves and cause significant pain, which will be aggravated by the stimulation when bending, resulting in a more pronounced pain that dares not bend. The fourth condition may be due to acute lumbar disc herniation, such as the rupture of the intervertebral disc when exerting force, lifting heavy objects, the nucleus pulposus is extruded beyond the annulus fibrosus, which will also stimulate the peripheral nerves and produce severe pain, and the pain increases when bending over and dare not bend over.