There are two main reasons for this condition: the first is due to lumbar muscle strain, such as frequent lifting, lifting heavy objects or twisting the waist during handling, as well as prolonged sitting, squatting, standing, etc. Keeping a posture for too long will lead to excessive fatigue of the muscle tissue of the waist, forming a local strain, which will form a local accumulation of metabolites such as lactic acid and inflammation, and after stimulation of peripheral nerves After the stimulation of the peripheral nerves, there will be a feeling of soreness in the lower back, that is, the symptoms of weakness and tiredness in the lower back. Secondly, there may be lumbar disc herniation, or local osteophytes and calcification, and chronic aseptic inflammatory lesions in the lumbar region, which can easily lead to a decrease in blood circulation in this area when straining or getting cold, and the accumulation of metabolites such as inflammation and lactic acid will stimulate the peripheral nerves, which will also lead to a feeling of lumbar weakness and fatigue.