Sitting in the car for a day back pain is because the muscles of the low back acute strain, acute strain after the lumbar muscle spasm, lumbar myofascia will produce aseptic inflammation, which produces low back pain. What should I do if I have low back pain? First of all, we should change the sitting position, stop labor, try to lie down to rest, rest can be localized hot compresses, the use of hot water bags or hot towels on the lumbar part of the local heat therapy, each time for 15 minutes, 3-4 times a day, to avoid excessive bending and down to the ground activities. You can also properly stretch the muscles of the lower back or gentle massage, avoiding strong massage, so as not to increase the local bleeding and adhesions. Oral anti-inflammatory and analgesic drugs or muscle relaxants can also be taken, commonly used anti-inflammatory and analgesic drugs such as diclofenac sodium, celecoxib, etc., commonly used muscle relaxants such as etoperisone, cloxazone, etc., which can effectively alleviate muscle pain.