Young people flash their back, i.e., lumbar sprain. A simple lumbar sprain can generally heal in about 1-2 weeks, but if there is a combination of small lumbar joint disorder or lumbar disc herniation, etc., the healing time may be appropriately extended. Lumbar sprain is relatively common in clinical practice, mainly due to lax muscles in the lumbar back, lack of exercise for a long time and improper posture, resulting in muscle strain in the lumbar back and consequently pain, some of which may be combined with local swelling. The main clinical symptoms of lumbar sprain are severe pain in the lumbar back and significant limitation of lumbar flexion and rotation activities. Conservative treatment of lumbar sprain is the main treatment, such as physical therapy with hot compresses, and can be combined with oral non-steroidal anti-inflammatory and analgesic drugs to relieve pain when the pain is severe, and can generally heal in about 1-2 weeks without sequelae. After a lumbar sprain, if there is a combination of radiating pain on one side of the lower limb, it is necessary to consider whether there is a lumbar disc herniation, and should promptly go to the orthopedic department of the hospital for examination.