Why do knuckles click?

Many people have this experience: when making a fist, the knuckles will suddenly make a bang, and some people even enjoy it. When bored or nervous, they take turns to hold their knuckles and "click"; Some people just go up and down the stairs, and their knees will have a rhythmic "quack" sound; Have a plenty of heel arch straight "pa" ring; Some people even stretch and yawn, and the back of the neck or teeth will make a sound. What's going on here? Breaking knuckles or other joints sometimes makes a "click" sound. What's going on here? When you knead or pull a joint, you sometimes hear a click. This is a kind of noise, that is, the pressure of lubricating fluid in joint cavity decreases and bubbles are generated. This sound may also be caused by the separation of the two ends of the joint and the release of the vacuum seal of the joint.

This kind of noise is sometimes heard in osteopathic treatment. However, noise does not necessarily mean successful treatment. Similarly, no noise does not mean that the treatment failed. To prove the success of osteopathy, normal range and freedom of movement are still needed. All soft tissues of human body, including joint capsule, contain dissolved nitrogen. When pulling the bone, for example, bending the finger hard, resulting in a vacuum in the joint space, nitrogen suddenly ran out of the liquid and entered the joint space, which would make a slight bubble sound.

If you grab the child by the arm and lift him up, and then do an X-ray examination, the doctor can often see a small crescent-shaped gas between the cartilage of the shoulder joint. That is the nitrogen accumulated in the joint space when the child is forced to pull his arm and the soft tissue fluid is exhausted. This gas can sometimes be seen at the hip joint.

Ultrasound examination of infants with congenital dislocation of hip joint can sometimes see some small bubbles moving rapidly in the hip joint. This is likely to happen if the baby cries and struggles and hugs the baby too tightly. These bubbles will disappear after nitrogen is dissolved again.

X-ray examination of fingers immediately after snapping their fingers may show a small bright spot between the knuckles, which is an image formed by thousands of opaque tiny bubbles concentrated there.