Sitting for a long time lumbar pain straight up, usually a chronic, long-term lumbar muscle strain performance, may be associated with excessive lumbar muscle pull, osteoporosis, lumbar disc herniation. 1. Excessive lumbar muscle strain: Insufficient exercise and sedentary lifestyle will lead to weakened lumbar muscle strength, and some of the muscles are in a state of tension, resulting in muscle fatigue and soreness, making it difficult for you to stand up straight. 2. Osteoporosis: when osteoporosis occurs in the lumbar vertebrae, the support function of the bones is weakened, and the pressure on the lumbar vertebrae increases after sitting for a long time, causing lumbar pain and making it difficult to stand upright. 3. Lumbar intervertebral disc herniation: Sitting for a long time can lead to lumbar muscle spasm, fatigue, etc., lumbar intervertebral space pressure increases, compression of spinal nerve nerve roots, causing lumbar pain, but also can be accompanied by one or two lower extremity radiating pain. Sitting for a long time lumbar pain straight up can also be seen in other causes, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for relevant examinations, with the help of the doctor to clarify the cause, and targeted treatment or treatment.