When exercising, you can often hear people make “rattling” sounds, such as squatting knee sounds, walking hip joints make a soft “rattling” sound, turn the neck cervical spine sound, clutching fingers to hear the sound of fingers … … … These sounds are often called “popping”. Generally speaking, only a popping sound, the appearance is not red or swollen, and do not feel pain, not accompanied by activity disorders belong to the physiological popping sound, do not need special treatment, and do not need to be too anxious about it. Especially for those who are sedentary, the lubricating fluid produced between the joints is less, which increases the loss of joint friction and makes it easier to hear the ringing. When accompanied by pain or limited joint movement, a hospital visit is required to determine if the joint is misaligned or damaged. However, from a physical point of view, the movement of a joint is nothing but sliding (such as the initial bending of the knee), rolling, grinding (rotation), etc. These are not free from mechanical principles, and will naturally produce sound due to friction and vibration, but because the joint cavity is completely closed and the synovial fluid is effectively lubricated, the sound is so small that it cannot be heard. When the joint first “moves”, the force of the tendon (such as tension) will instantly cause the joint to deform, up to 7%, and the deformation produces negative pressure in the joint cavity. Although the negative pressure is slight, it is enough to make the joint capsule depressed (inhaled), so that the nitrogen, oxygen, carbon dioxide and other gases dissolved in the synovial fluid are partially vaporized into bubbles. When the action is completed, the bubbles and the synovial fluid are compressed, which is like opening a champagne “bang”, popping the depressed joint capsule back to its original shape, and the gas dissolves back into the fluid again. Because it takes time for the gas to dissolve again, the knuckle sound can be repeated, but not continuously. Of course, in addition to this mechanism, sounds from the knee, ankle, or back may also be caused by a tense tendon “walking” slightly during joint movement and then springing back to its original position, or by a large friction with the joint bulge, resulting in a loud sound. It is now known that normal joints are under negative pressure in resting conditions. When the joint becomes inflamed, the cavity pressure rises, which is not only painful but also detrimental to the survival of cartilage cells. Therefore, proper tendon stretching exercises to reduce joint pressure should theoretically be effective in improving joint degeneration, and certain movements of yoga may coincide with this. As for joint degeneration and pathology, such as degenerative arthritis, cartilage breakdown, and rupture of the semilunar cartilage of the knee, the sound emitted is usually accompanied by other symptoms and pathological changes, which are not the joint sounds described in this article, and should not be confused. For this symptom, we should improve the function of the joints through medication as early as possible. For your neck soreness and sound problems, it can play a role in relief and rehabilitation.