Chondromalacia patellae is a common name, the exact term is patellofemoral joint cartilage injury. It is a common and frequent disease, which used to be seen mostly in middle-aged and elderly people. In recent years, with the popularity of sports and fitness, the incidence is increasing among young people. The main symptom is knee pain, mainly when the force is painful, jumping pain, up and down stairs pain, squatting difficulties, often feel weak, playing soft, joint activities can be loud, friction. Continued development may result in pain when walking on flat surfaces and joint swelling. There may be no abnormalities or mild degeneration on radiographs. Treatment may include topical medications, ultrashort wave physical therapy, oral glucagon, Vigorix, etc. At the same time, quadriceps strength training (static squatting exercises) should be performed. With treatment, the symptoms usually disappear. It is worth noting that the symptoms of the disease are often caused by strenuous exercise, such as climbing mountains, stairs, dancing, tai chi, repeated squatting exercises, etc. Therefore, the above exercises should be avoided. If the symptoms persist, an axial patella film should be taken to see if the patella is tilted, and if it is tilted, surgery can be considered.