The knee is the largest weight-bearing joint of the human body, and the normal knee joint can bear an average of 35 kg. The more weight you bear, the greater the chance of articular cartilage wear, the tendon is also prone to injury, and the knee joint degrades faster. According to expert research statistics, the knee weight multiples are as follows:

1. When lying in a supine position, the weight of the knee is almost zero. 
2. When the steps are up and down, the weight of the knee is about 3-4 times the weight. 
3. When running, the weight of the knee is about 4 times.