Knee pain without trauma in daily life may be due to the following reasons: 1. It is due to subpatellar fat pad strain, which means that the patient often walks long distances, as well as squatting, climbing and other high-intensity exercises, and induces pain. 2. It may also be due to synovitis of the knee joint, which can lead to knee pain or increased pain when flexing. 3. 4. The pain is caused by free bodies and osteophytes in the knee joint, or by arthritis, which can cause pain.