Flash to the waist, clinically known as acute lumbar sprain, the main symptoms include lumbar pain, muscle stiffness, activity limitation and so on. 1. Lumbar pain, stiffness: acute lumbar sprain is a common clinical disease, mainly caused by the lumbar sudden force and other reasons. Patients will first manifest as lumbar pain, the nature of the pain is more intense, the site is relatively fixed, the pain can be aggravated after activity, can be relieved after rest; also due to pain and metabolic product accumulation caused by local muscle edema, stiffness and even spasm. 2. Restricted activities: sprain more serious patients, but also due to pain or lumbar small joint disorders and lumbar activity is limited, patients are often manifested as a fixed position or forced position, that is to say, tend to take the position of the slightest pain to relieve. When the sprain patients appear lower extremity radiating pain, numbness and other symptoms, need to be alert to the existence of lumbar disc herniation. If the symptoms are not relieved, or accompanied by other symptoms, you should go to the hospital in a timely manner, to clarify the cause and then give targeted treatment.