Meniscal injury of the knee is a disease with limited pain in the knee joint, some patients have beaten soft leg or knee joint interlock phenomenon, quadriceps atrophy, and limited pressure pain fixed in the knee joint gap as the main manifestation. Meniscal injuries are mostly caused by torsional external forces. When one leg is weight bearing and the lower leg is fixed in semi-flexion and external booth, the body and the femur are violently rotated internally and the medial meniscus is subjected to rotational pressure between the femoral condyle and the tibia, resulting in meniscal tears. 1, how to avoid knee meniscus injury 1, sports before full preparation, especially the joint parts of the warm-up exercises, stretching ligaments, gradually open the joint, so that the joint response flexible; 2, do not in a fatigued state of sports, when the human body movements are not easy to coordinate, easy to cause meniscus injury; 3, usually strengthen the muscle strength training around the knee joint to increase the stability of the joint; 4, pay attention to the joint proprioception. 4, pay attention to the joint proprioceptive training; 5, suitable sports venues and sports shoes is necessary; 6, strenuous confrontational sports, pay attention to self-protection, effective protective gear is needed; 7, if there are symptoms of meniscal injury, to stop sports, knee braking, and timely medical consultation. Second, the symptoms of meniscus injury 1, knee pain; 2, joint swelling and fluid; 3, joint interlocking; 4, playing soft leg; 5, joint ringing.