Cartilage wear and use of machines is the same reason, the machine use more, will certainly produce wear and tear, the use of a long time, the intensity, wear and tear will also increase, so the human joints will also wear. The causes of cartilage wear are as follows: 1, overuse in the process of use, such as long-term sports, high-intensity sports, like running these sports, the use of intensity is relatively large, the wear and tear is relatively fast; 2, the longer you use, the more wear and tear will be, just like the machine. Also related to age, for example, the older you are, the longer you use, the more wear and tear will be; 3, the degeneration of the elderly will lead to thinning cartilage, cartilage is a layer of white brittle bone on the surface of the joint, when you are young, more water, more elastic. As we age or use too much, it will degenerate, degeneration, such as water reduction, elasticity, and even rupture, defect, this possibility. If the cartilage is ruptured or defective, it may be difficult to grow and has to be treated surgically.