Knee pain after prolonged sitting is common for the following reasons: 1. osteoarthritis of the knee joint, the patient will have knee joint pain, restricted movement, if sedentary, will make the knee joint stiff, and will be accompanied by painful symptoms, X-ray examination will find joint space narrowing, joint osteophytes. 2. rheumatoid arthritis of the knee joint or rheumatoid arthritis, the patient will have obvious joint stiffness, especially in the morning. There will be a severe inflammatory reaction in the joint, affecting the joint to walk with weight, and the rheumatic examination of the knee joint will be positive. Knee pain after prolonged sitting must be treated early, otherwise the function of the knee joint will be seriously impaired. Patients should also strengthen the protection of the knee joint and exercise of the muscles around the knee joint to prevent the symptoms in general.