Low back pain and weakness may be related to the following causes: 1. It may be due to fatigue factors. The patient is often bent over to pick up things or a wide range of activities involving the waist, which may cause strain on the lumbar muscles after a long period of time, leading to lumbar pain and weakness. 2, may be due to the impact of poor posture. There are many patients who often need to sit and stand for a long time, and when they sit and stand, their sitting posture is not correct, such as having a cross-legged or hunched over back. This can cause spasms in the lumbar muscles, which can lead to back pain and weakness. 3. may be caused by peripheral nerve lesions. The most common one is lumbar disc herniation, which can also cause back pain and weakness. 4. It may be caused by osteoporosis. This condition is most common in the elderly. Once osteoporosis is produced in patients of this age, it often manifests as pain in the lower back and lower limbs, and soreness and weakness. 5. It may also be caused by a deficiency of kidney essence. However, this is a concept within Chinese medicine. Its main meaning refers to the patient’s kidney deficiency due to room strain or excessive exertion, etc., followed by the symptoms of soreness and weakness in the waist and knees.