The causes of pain in the front of one knee are as follows: 1. Pain in the front of the knee may be caused by osteoarthrosis of the patellofemoral joint, chondromalacia patellae, Achilles tendonitis, and tendonitis of the quadriceps muscle. 2. If the pain is in the back of the knee, it is commonly caused by posterior joint injury, meniscal injury, tendonitis, or popliteal cyst. 3. 4.It may be an injury to the lateral collateral ligament, that is, too much exercise leading to fatigue inflammation of the lateral collateral ligament, causing pain in the lateral knee. 5.If there is pain in the medial knee, it may be due to strain, too much exercise, too much strain leading to fatigue inflammation of the medial collateral ligament of the knee. 6.It may be the medial knee 7. Medial joint pain may also be due to injury to the medial meniscus, which causes pain in the medial space of the joint. Therefore, if the symptoms of knee pain appear on one side, after bed rest, local physiotherapy, avoiding strenuous activities and other conservative treatment measures, the symptoms are not relieved within a short period of time, you must promptly go to a regular hospital to improve the MRI examination of the knee joint, combined with the patient’s medical history, signs and symptoms, and then choose a more reasonable treatment method.