If the eyes are the windows to the soul, then "knees" are the key to physical activity! If your knees always hurt, it means that the cartilage inside the knee joint has worn away, causing the knee joint to degenerate. At first it is just painful, but over time, the cartilage is used up and the knees hit each other directly. It may hurt when you move, and you can only lie in bed. Lying on the bed will cause muscle atrophy, causing the knees to become more worn and painful. As the joints continue to degenerate, they will never be able to return to a state of free movement.
However, the way you injure your knees may be different from what most people think. Because the knee is originally used for bending, it originally has a "track" between bones and cartilage. If you walk along this track and rest in time, you will not easily injure your knee. What causes knee injuries is because the bones are out of track. Abnormal friction will cause knee degeneration.
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