The knee joint is the joint of the upper and lower leg , the middle of the meniscus, the front of the patella, the patella is stretched by two muscles, suspended in the leg before the junction, very easy to slide, in normal life, due to the impact of external forces, there is no strenuous exercise, so the patella in the knee can be normal small range of activities. Due to excessive pressure on the knee in mountaineering, running and some ball sports, coupled with intense exercise in mountaineering, it is easy to make the patella be pulled away from the original part, which causes diseases in the knee joint. The patellar strap can fix the patella in a relatively stable position to ensure that it is not easily injured. The above is the role of the patellar band when the knee is not injured. After the meniscus is injured, the use of the patellar band can reduce the friction of the meniscus, slow down the pain, and protect the knee joint from aggravating the condition.