The reason for the reduction of low back pain after activity may be because of a long-term posture, lumbar muscle tension, stiffness, and thus muscle spasm, long periods of inactivity inflammatory substances accumulate, poor blood circulation, after activity helps to promote blood circulation, helps to reduce muscle spasm, and after activity muscle stretching can be relaxed, thus accelerating blood flow, improving blood circulation, taking away the accumulated inflammatory substances and reducing stiffness It can make the back pain lessen. But lumbar muscle inflammation is a relatively light case, if too much activity, exertion or cold after, will pain but again aggravated. Some low back pain after activity and muscle tension is not related, just activity to distract the local pain, attention, may be urinary stones, inflammation, etc., after the activity of the stone position change, so that the card pressure to reduce, thus reducing pain, later if the pain again, but also need to go to the hospital to check clearly before treatment is better.