Lower back pain during breastfeeding is mainly due to the fact that during breastfeeding, the body is weaker after giving birth and is prone to fatigue. Coupled with the frequent carrying of babies with heavy loads, it will lead to continuous fatigue of the muscles in the lower back, long time will form strain, which will stimulate the peripheral nerves around the pain. After the strain, more lactic acid will be produced, so there will be a feeling of soreness in the lower back. This, combined with the fact that the strain consumes more energy and electrolytes, can lead to weakness and tenderness in the lower back. In addition, there is often a combination of cold, which causes the muscles in the lower back to become more tense, consuming more energy and electrolytes. And because the cold will lead to a further slowing of blood circulation, vasoconstriction, arterial blood supply will be reduced, local nutrition and energy support will also be reduced, the slowing of venous return will lead to inflammation and lactic acid gradually build up, which will aggravate the feeling of pain and soreness.