Watch out! Do your knees make a "cracking" sound when you stand up or squat?

Expert of this article: Wang Qiuyuan, Beijing University of Chinese Medicine, Doctor of Medicine

This article was reviewed by: Liu Pei, Associate Chief Physician, Artificial Joint Revision Department, Zhengzhou Branch, Henan Orthopedic Hospital

In daily life

I believe many people have had this experience.

Sometimes when I stand up or squat

You will hear a "click" sound from your knee

Many people think

It's no big deal

But many people also feel

This is a sign of knee disease.

So what exactly is the cause of this?

Let’s watch…

What causes knee popping?

Many people experience knee joint clicking, which is also called knee popping. This popping is related to the friction between the tissues and structures of the knee joint and the change in pressure in the knee joint cavity. It can be a normal physiological manifestation (physiological popping) or a sign of knee disease or even injury (pathological).

How to determine whether it is physiological or pathological?

Physiological snapping mainly occurs when the joint is suddenly stretched. The joint cavity itself has negative pressure to maintain the relative stability of the joint. This negative pressure environment is stable when the joint is stationary. When the joint is suddenly stretched, the stable negative pressure of the joint cavity has no time to change. The pulling force is greater than the negative pressure of the joint cavity, and the joint cavity will diffuse gas like a sudden wind, resulting in a crisp sound.

This popping sound occurs when the joint is subjected to instantaneous force under static conditions, and it does not last. There is a feeling of relief after the sound, which is very pleasant, because after the sound the negative pressure in the joint cavity has reached a balanced and stable state again.

Pathological snapping is mainly caused by abnormal friction of the joint structure. Due to aging and degeneration of the joint, wear and tear of the joint structure, bone hyperplasia, and collision with the joint soft tissue, etc., its characteristic is that the snapping is related to movement, may be continuous, and have a crushing sound, often accompanied by pain and even joint compression that affects movement.

There is also a sound related to the acute rupture of the knee ligament, which often occurs when the knee joint is suddenly sprained during strenuous exercise, causing the acute rupture of the anterior cruciate ligament. In addition, the Achilles tendon rupture caused by the sharp bounce during basketball will also produce this tearing sound.

What other symptoms does knee joint disease have?

The knee joint is composed of the meniscus between the femur and tibia, the patella, and the soft tissues of the knee joint (joint capsule, cruciate ligaments).

Pathologies of these structures may cause pain and limited movement of the knee joint, and of course they have their own characteristics, such as:

1. Knee osteoarthritis is mainly caused by wear and peeling of the knee cartilage. It often occurs in the elderly. The pain will worsen after activities. The course of the disease is very long and gradually worsens. It is often accompanied by joint deformities, namely O-shaped legs and X-shaped legs.

2. Meniscus tear is often accompanied by a history of knee sprain, which manifests as the joint suddenly feeling stuck.

3. Rheumatoid arthritis often manifests itself as stiffness and pain in the joints, which is especially obvious in the morning. However, the stiffness and pain will improve after activity, and there is often a family history of this disease.

How to protect the knee joint?

First, you should pay attention to keeping your legs warm, because coldness may induce synovitis of the knee joint.

Second, you should improve your lifestyle and exercise habits, reduce prolonged weight-bearing activities on the knee joints, climb stairs less often, and don't squat for too long.

Wear a knee brace during strenuous exercise to increase knee joint stability.

Recommended exercises include swimming, cycling, and other sports that put less load on the knee joints. If you want to run, run on flat roads as much as possible.

The third is to strengthen the muscles around the knee joint, especially the quadriceps, which is very helpful in increasing the stability of the knee joint.

Fourth, when knee pain cannot be relieved by conventional over-the-counter treatments (such as massage, oral topical anti-inflammatory drugs), you need to seek medical attention in time to clarify the condition as soon as possible to avoid further aggravation of the injury.

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