Why does the knee ring?

It's called joint snapping. Because joints rub against each other during movement, sounds will be made between articular surfaces, between cartilage pads and articular surfaces, between tendons and joint capsules, between tendons and bones, and between tendons and tendons. This kind of snap caused by physiological activities of joints is physiological snap. In most people, this sound is not obvious and inaudible, but in some people, it is more obvious and sounds clearer. This is caused by individual differences. Those who only blink without painful dyskinesia belong to physiological blink.

Joint fracture may also be pathological. If it is caused by knee joint injury or old age, it is better to go to the hospital to see if it is safe.