If the pain is caused by ankylosing spondylitis or rheumatoid rheumatism, the patient should be registered with the Department of Rheumatology and Immunology, Second, orthopedics, if the pain below the waist and above the buttocks is caused by sacroiliac arthritis or dense osteoarthritis, orthopedic consultation and treatment can be carried out, these two diseases can often appear in the sacroiliac joint pain and percussion pain, in the X-ray and CT can be seen in the sacroiliac joint significantly increased density, joint space narrowing, to early Physical therapy as well as oral medication are required.