Do not do strenuous activities as well as bending activities after flashing waist. Flash back is acute lumbar back sprain, may be due to participate in activities or physical labor caused by acute lumbar sprain, must pay attention to rest, temporarily not engage in strenuous exercise, otherwise it will lead to aggravation of the injury, and to avoid bending activities, bending activities, often feel the pain in the lower back obviously, and easy to lead to aggravation of the condition. Acute low back sprain can be taken within 72 hours of local cold compresses, after 72 hours, can be taken to hot compresses, massage and physical therapy, such as ultrasound, infrared, etc., generally can promote local blood circulation, relieve pain symptoms. In addition, acute low back sprain recovery period can be appropriate exercise, but appear uncomfortable immediately stop. After acute low back sprain, try to go to the hospital in time, cooperate with the doctor to take treatment or treatment.