Lumbar spine minimally invasive fusion surgery for 45 days, walking back or sore legs have no strength, the most common reasons are soft tissue adhesion, muscle atrophy, and so on. 1. Soft tissue adhesion: after minimally invasive lumbar spine fusion surgery, the patient needs to stay in bed for a period of time, and the reduction of joint activities will easily cause soft tissue adhesion, which will lead to lumbar soreness and lack of strength in the legs when walking. 2. Muscle atrophy: prolonged bed rest is also likely to cause the patient’s muscle fibers to decrease in mobility, which will lead to muscle atrophy, and will also show a lack of muscle strength, which will lead to leg pain and weakness. Cause lumbar spine minimally invasive fusion surgery 45 days of walking waist or sore legs have no energy for more reasons, if the symptoms continue to have no relief, it is recommended to promptly go to the hospital to find out the cause of the disease, by the doctor targeted treatment.