The causes of lumbar stiffness and bending are common in the following diseases: a. The most common cause of lumbar stiffness and bending is ankylosing spondylitis, when suffering from ankylosing spondylitis lesions occur in the small joints of the spine, resulting in significant joint hyperplasia and significant calcification of the ligaments, which will eventually lead to lumbar stiffness and no way to bend. When rheumatic and rheumatoid diseases invade the spine, it leads to very obvious stiffness, although not as serious as the damage caused by ankylosing spondylitis, but also leads to the stiffness of the inability to bend. Third, suffering from lumbar disc herniation may also produce the inability to bend the waist and lumbar stiffness, but the situation is relatively mild.