Cracking bones does indeed cause damage

Finger crackingNoises from synovial fluid

You cross your hands and then push them outwards or pull on individual fingers. A small movement, a small noise, but a broad effect: those who do it get a pleasant feeling: "I actually do this to relax the hands." As if the cracking of the fingers would loosen any blockages. For others it is a horror. This has to do with evolution: A sharp noise like the cracking is associated with danger: Warning - someone is sneaking up on you! Or: be careful - something breaks! "I often think about the fact that my mom used to say to me: man, you shouldn't do that, it will break your joints". Today Dr. Martin Lautenbach orthopedic surgeon, head of hand and foot surgery at the Waldfriede Hospital in Berlin and assures: "We know today that this is nothing bad at all, that it cannot cause any damage at first."

However, science has long been divided on this: a 1990 study found that those who regularly cracked their fingers for years were more likely to have swollen hands. But: Among them were significantly more people who did heavy physical work, drank more alcohol and smoked more than in the comparison group. So the damage could not be clearly attributed to the cracking of the fingers.

A self-experiment provides the first results

In 1998, the American doctor Donald L. Unger reported in a letter to the magazine "Arthritis und Rheumatismus": Mother, aunts and even his mother-in-law had warned him from childhood: You will get arthritis from it. He then tried to do it himself for 50 years and cracked the joints of his left hand several times a day. He left his right hand alone. The result, documented with an X-ray: Both hands look the same. The American added humorously:

"These results strongly question whether other parental advice, for example about eating spinach, is wrong."

Unger's self-experiment was then confirmed by several scientific studies: Even with regular finger cracking, there are no signs of wear and tear on the joints, no osteoarthritis and also no inflammatory processes, i.e. rheumatoid arthritis. Because, adds Dr. Martin Lautenbach added:

"Rheumatism is a chronic inflammatory disease affecting the entire body, so it has nothing to do with the movement you do, rheumatism and osteoarthritis cannot be triggered by cracking your fingers.

It is also in the nature of things that cracking fingers is not harmful. Because now we know the answer to the question that Eckart von Hirschhausen asked in his "Quiz des Menschen":

"What makes the sound of your fingers cracking?"

The cracking noise has to do with the synovial fluid

Here, too, science was not in agreement for a long time, says hand surgeon Dr. Martin Lautenbach:

"There were a lot of theories: The joint pops out, we know today, no, that's not how it is. It was thought that the joint capsule is somehow stuck together, the person who makes this finger-cracking movement stretches the capsule, we know today: no, that's not it either. "

British researchers had the idea as early as 1947 that the cracking had something to do with gas bubbles in the so-called synovial fluid in the joint gap:

"This fluid consists of several parts, we have the synovial fluid, which consists of proteins, which also consists of real water and collagen fibers, that is, from such small connective tissue fibers. And we know that small air bubbles can also form around the proteins . "

The synovial fluid prevents bones from rubbing against each other, but also keeps them in the correct position despite movement. If a joint is now overstretched, pulled apart, a negative pressure and a kind of cavity is created at a certain point:

"And you know that these little bubbles open with you, and that acts like a kind of balloon pop."

However, it was still unclear whether the noise arises when the gas bubbles are generated in the liquid by the negative pressure or only when they burst. In 2018, American and French researchers carried out a mathematical analysis of the processes in the joint and found that both are correct:

"By pulling the joints apart, the gas bubbles that are trapped in the liquid are first under pressure, like when opening a soda bottle. But at the same time they burst. Plenty of dissolved gas remains in the liquid itself for the next time, tiny bubbles, which the pressure has practically not reached. "

Conclusion: cracking your fingers is harmless

Deliberate finger-cracking is therefore not harmful, and if it helps with stress relief, you can do it with confidence. However, one should not only pay attention to the cracking, but also to other body signals:

"If this causes pain, then you should definitely look first, where the problem is coming from, and second, you shouldn't make this movement."

Because: Diseased finger joints can also crack.

"And the causes can be in the area of ​​the tendons, for example, that the tendons can no longer slide normally in their canals, which is certainly the most common form of clicking or snapping fingers that can trigger a really loud crack, and you can But I also have to say that in the case of advanced cartilage wear diseases, arthrosis, cracking noises can also arise, especially when the joints are already significantly damaged, then it is really worthwhile to have this clarified by a doctor. "

This is where the topic of rheumatism comes into play again: Cracking fingers does not trigger rheumatism, but:
"People who notice, for example, that joints start to snap, and pain and swelling suddenly appear, that can very well be a very early sign that a rheumatic disease is developing, because that is the first place where rheumatism occurs in the area of ​​the finger joints, in the area of ​​the wrists. "

But - as I said: there is no health risk with deliberately induced pain-free finger-cracking - unless you make the involuntary listener frenzy.