Knee pads A vest worn on the leg is a knee pad, which is mainly used for sports protection, cold protection and joint maintenance. Knee pads have three functions, one is braking, the other is heat preservation, and the third is health care. Among them, the most important function is the braking function of knee pads. Knee joint is the intersection of thigh bone and calf bone, with meniscus in the middle and patella in front. The patella is stretched by two muscles and suspended in front of the intersection of leg bones, so it is very easy to slide. In normal life, the patella can move normally in a small range because it is not affected by external forces and does not exercise vigorously. Due to the excessive pressure on the knee in mountaineering and the strenuous exercise in mountaineering, it is easy to pull the patella away from its original position, thus causing knee joint diseases. Wearing knee pads can fix the patella in a relatively stable position and ensure that it is not easy to be injured. What is mentioned above is the gentle braking effect of the knee pad without injury to the knee joint. After the knee joint is injured, the knee pad with heavy braking can reduce the knee bending, keep it in a straight line from thigh to calf, and reduce the knee bending, thus protecting the knee joint from aggravating the disease.