Back discomfort, feeling tight, this situation is usually due to two reasons: 1, is due to long-term low ambulation, bilateral elbow joints without support, elbow joints continue to hang; or bending too long, it will lead to the back muscles continue to be in a state of tension, over time there will be fatigue, and even strain injury. This will form a sterile inflammatory lesion in the back, inflammatory metabolites stimulate the peripheral nerves, there will be a feeling of muscle tightness. 2, is due to the back has a cold situation, because after the cold local temperature drops, the muscles will be in a state of tension, and from the muscle through the blood vessels will also be contracted, resulting in slowing down the blood circulation. If the arterial blood supply decreases, the muscle tissue will not get enough electrolytes, nutrients and energy support, and the feeling of tightness will appear; and after the venous return is slowed down, lactic acid and metabolic products will accumulate, and the feeling of tightness will appear.