Four postures to strengthen knees and treat pain

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.