Lumbar flash is often referred to as acute lumbar sprain, after the injury can be from the symptoms, signs, imaging and other aspects of the comprehensive judgment of the seriousness of the injury. 1. Symptoms and signs: the main manifestation of mild lumbar pain, pain site is relatively fixed, activity is limited, and the pain can be exacerbated after the activity. If there are symptoms such as lumbar deformity, muscle spasm and localized pressure pain, accompanied by lower limb numbness and even incontinence, the condition is relatively serious. 2. Imaging examination: If there is no obvious change in X-ray examination, the condition may not be serious; if there is lumbar vertebral fracture, the condition is serious. Generally, there is no need to do CT or MRI, but if there is a high suspicion of spinal cord injury, you can choose to do this test. If spinal cord injury is determined to exist, it indicates a more serious condition. Acute lumbar sprain should go to the hospital in time, and the doctor will judge the severity of the condition according to the patient’s symptoms and signs and imaging examination, and give appropriate treatment.