Common causes of low back pain and knee pain include the following: i. Osteoporosis, due to osteoporosis resulting in bone loss and abnormal bone metabolism, pain is likely to occur in the weight-bearing parts of the waist and knee. Second, it can be seen in ankylosing spondylitis, due to the effect of ankylosing spondylitis, there will also be corresponding back pain as well as joint pain, also including knee pain. Third, it can be seen in high lumbar disc herniation, for example, the lumbar 2-3 disc herniation can easily lead to the compression of the femoral nerve root, and low back pain as well as knee pain. Patients are advised to go to the hospital for detailed examination, including bone density examination, imaging examination of the lumbar spine and knee joints, and to carry out the corresponding treatment after a clear diagnosis.