Knee pain when jumping may be caused by inadequate cushioning, knee joint inflammation, meniscus injury and so on. 1. Buffer action is not in place: jump landing, due to gravity factors for the knee pressure is very large, if the jumpers do not carry out appropriate buffer action, may cause soft tissue contusion, resulting in knee pain. 2. Knee joint inflammation: such as osteoarthritis, rheumatoid arthritis, this kind of disease has aseptic inflammation in the knee joint cavity, and when jumping, it pulls the inflammation lesion, and pain symptoms appear. 3. Meniscus injury: knee pain when jumping may be due to meniscus injury, meniscus connecting the lower end of the femur, tibia upper end, if meniscus injury, the knee joint will lose stability, which will lead to direct collision of the bone, contusion, which triggered pain. Jumping knee pain, there may also be other reasons such as anterior cruciate ligament injury, etc. If the pain symptoms are serious, it is recommended to consult a doctor in a timely manner, a clear diagnosis, targeted treatment.