Until now, people knew the sound of 'green' when breaking the joints from where

What we see is an extremely high signal on the ultrasound image, like a series of fireworks that were shot in the joint.

Find out the "green" sound when breaking the knuckles

Have you ever wondered where the cries heard when you cracked your joints? Is it the sound of the bones touching each other, the tendons being stretched and suddenly turned back or are the air bubbles broken in the synovial fluid? To explore this, scientists had to use both ultrasound and magnetic resonance machines. Yet they still have not ended the controversy that has lasted for decades about the mysterious "green" .

Where does the "rattle" sound when breaking joints come from?

In April, a team of researchers from the University of Alberta published a scientific paper explaining that the "clash" of joints came from broken air bubbles. They are bubbles that exist in liquid fluid that surrounds joints. However, because ultrasound technology is simple and 100 times faster than magnetic resonance, a group of other scientists decided to use it to further investigate the problem.

Led by Robert D. Boutin, a diagnostic imaging specialist working at the University of California, Davis, researchers in the team selected 40 volunteers to participate in the survey. 30 of them often break their knuckles, the remaining 10 do not have this habit. Even an older volunteer admitted that he had broken his knuckles about 20 times a day for 40 years.

Volunteers were asked to break the metacarpophalangeal (MPJ) joint on their hands. This is the joint where the fingers are merged with the hand. Meanwhile, doctors set up an ultrasound machine and a recorder to monitor the corresponding images and sounds of each joint. 400 tests were recorded.

While the researchers waited for an image with a time resolution 10 times higher than a magnetic resonator, the end result was too surprising."What we saw was an extremely high signal on the ultrasound image, like a series of fireworks that were fired in the joint, " Boutin said.

These signals coincide with the "green" sounds that the joints create. And so, with ultrasound imaging, the researchers were able to accurately predict 94% of the joints that could produce noises and no joints. Boutin explained on Metro:

"There have been some inconsistencies that explain what happens when we break joints over the years. Our research shows that noises are associated with unusually high signals in Ultrasound images that support the hypothesis it is the result of changing pressure and air bubbles in the joints. "

Air bubbles inside the synovial fluid of the joint.

It was like that, but it didn't seem to end. While the sound of "rupture" of joints is recognized by many scientists regarding the air bubbles inside the synovial fluid, they continue to argue about the bubbles coming before or after the noise.

Back in 1947, there was a scientific article saying that the "rupture" of the joint came from a gas bubble forming inside the synovial fluid. This hypothesis 30 years later was rejected and scientists then believed that noise came from broken bubbles.

April experiments by University of Alberta scientists reaffirmed the theory that bubbles exploded . However, a convincing evidence has yet to be recorded. In short, the "continental" sound comes from the air bubble forming or exploding?

"It's a sensitive question and hard to answer , " Boutin said. "I can only say that mutations in ultrasound images always come after we hear the noise. There are no exceptions. Perhaps that is evidence to support the hypothesis of the bubble. forming, not that they are broken ".

Although there is still controversy surrounding the air bubbles, scientists agree on another aspect. They claim that there is no sign of areas of swelling, pain or injury inside the joints when we break them "green". There is no difference in joint condition among people who often break them 20 times a day with 10 people who do not have the rest.

The results were also compared with another study by a doctor in California. Donald Unger, he spent 60 years to break a hand joint regularly and leave the other side intact. The result is that there is no difference between the two hands when he does that. However, the effort brought him an Ig Nobel prize.

Donald Unger, Ig Nobel prize laureate, broke the joint on one hand for 60 years.

Although much evidence is given about the innocence of cracking, Boutin remains cautious in his conclusions. He said more research is needed to really confirm that daily cracking does not cause damage to the system. However, he also expressed expectations on a reverse outcome."After each joint break, their range of movement increased significantly. Maybe it was a good habit."