Chondromalacia patella is a common disease of the knee joint, occurring in young adults, especially among athletes and sports enthusiasts, with a higher incidence in women than in men. The main pathological changes are degenerative changes in the cartilage, including swelling, fragmentation, and loss of cartilage, and finally the corresponding parts of the femoral condyles also undergo the same lesions, developing into osteoarthritis of the patellofemoral joint. The precautions and maintenance of chondromalacia patellae are those 1. Before exercising or participating in sports, warm up by walking or riding a stationary bicycle, and then do stretching exercises. Stretching the muscles in the front (quadriceps) and back (N cord) of the thigh can reduce the tension of the tendon and reduce the pressure of the patella acting on the patellofemoral joint surface of the knee during activity. 2, through special exercises to increase the strength of the lower limb muscles, because the muscle strength of the lower limb is very important for the stability of the knee joint, generally people with more developed quadriceps have a lower risk of knee arthrosis. One way to do quadriceps exercise is to do quadriceps isotonic contraction exercise, exercise when sitting on the edge of the bed, knee joint in the edge of the bed, then straighten the leg, adhere to three to five seconds and then put down, so repeat the exercise, 500 times a day. Second, the quadriceps isometric contraction exercise, exercise will be the front of the thigh muscle contraction, until the sleepy sore relaxed, so that the exercise 200-300 times a day. We are not in favor of strenuous exercises, such as mountain climbing, stair climbing, etc. knee flexion position hard exercise. 3, avoid sudden changes in the intensity of exercise, to enhance the strength and endurance activities should be gradual, gradually increase the amount. Obesity will increase the risk of degenerative diseases of the knee (chondromalacia patellae, osteophytes), which will form a vicious circle, the greater the weight, the heavier the pain; conversely, the lighter the weight, the lighter the pain, so weight will be a factor to consider when treating chondromalacia patellae and osteophytes. 5, wear the right shoes, preferably not high heels, when walking or running, the most is to wear shoes that help maintain body balance and lower limb force line. If you have the habit of running and exercising, it is best to wear shock-absorbing shoes when running, and you should also pay attention to changing shoes regularly. Before participating in confrontational remote sports activities, check whether your shoelaces are too long. 6, try to avoid deep squatting movements, such as duck steps, etc., to keep the knee joint in a pain-free range of motion. 7, Do not run down limp unless your quadriceps are particularly developed. 8, If you have knee pain you should insist on a knee brace or patella protector.