What's wrong with the sound when I bend my knee

When we exercise, we often find a common problem, that is, the knees make a noise when we squat. Some people may also experience other symptoms, such as knee pain and other problems. However, this kind of sound in the knee must be caused by incorrect exercise timing or method. There should be no problem with normal knees and it will not affect walking. Why is there a noise when you bend your knees?

Before introducing why the knees make noises, let us first understand what our knees look like. In fact, our knee is a very complex structure. It is not a simple piece of bone, but is composed of three parts: tibia, femur and patella. It has two joint structures, including the tibiofemoral joint and the patellofemoral joint. The synovial layer of our knee joint capsule and the articular cartilage together form an enclosed cavity with a small amount of synovial fluid and negative pressure. This is our joint cavity, as shown in the picture below.

After understanding the structure of our knees, let’s talk about why our knees make sounds. In fact, there are two reasons why the knees make noises: physiological and pathological. The physiological sound is generally caused by changes in the pressure in the joint cavity when our knees move. The gas in the synovial fluid precipitates to form bubbles. Multiple small bubbles fuse into large bubbles. When the large bubbles burst, they make a sound. This is the reason why the physiological knee makes a sound. Generally speaking, the noise caused by this reason is harmless to the body and does not require treatment. But remember not to make your knees make sounds on purpose. After all, the knee is a very delicate part, and always doing stretching or flexing movements is not good for the knee.

As for pathological knee sounds, there are many possibilities, which are generally related to meniscus damage. In addition, lesions or anatomical abnormalities of the synovium, cartilage, ligaments, and tendon tissues around the joints may also cause joint noises.

If your knee makes a rubbing sound instead of a clicking sound, it often indicates that your joint surface is uneven. Under normal circumstances, the surfaces of adjacent joints are covered with a layer of articular cartilage. The surface of the articular cartilage is very smooth and does not make any abnormal noise when they rub against each other. If your knee not only makes unusual noises, but also has slight pain or redness and swelling, it is recommended that you go to the hospital for a comprehensive examination. After all, knee health is related to our walking and exercise, so don't take it carelessly.