There is a new twist in the debate over why ankles crack.
Yes, it turns out that "why crack ankle" is actually a debate – despite the existence of the phenomenon for about the whole of human history, researchers still do not I do not know why it happens. And that's not due to a lack of understanding: researchers have investigated this issue since the early 1900s, according to a new publication in Scientific Reports.
The new publication postulates that ankle tears are due to the collapse of tiny air bubbles in the fluid that surrounds the joints. A 2015 study on this topic essentially came to the opposite conclusion: The crackling sound is created when these bubbles form, not when they burst open.
Snap Crackle Pop
Over the years, scientists have hypothesized that the distinctive sound of cracking could come from anything, from tissue vibrations to the tightening of joint capsules to collapse or blistering. This blistering is called cavitation and occurs when the fluid synovial fluid that lubricates the joints is pulled apart, resulting in a sudden pressure drop and a resulting gas-filled space. In the case of compounds, the gas is about 80 percent carbon dioxide, said Vineeth Chandran Suja, a graduate student in chemical engineering at Stanford University, who is studying bubble dynamics.
Suja began researching the ankle-crack puzzles by researchers from The University of Alberta in Canada that they introduced an expert-crunching-cracker to a magnetic resonance imaging (MRI) machine and observed the process in real time. The team found that the crackling noise was accompanied by the formation of cavitation bubbles in the joint.
Genesis or collapse?
This statement Suja appeared suspicious. The size of the blast seemed too great to be blistered, he and his co-author Abdul Barakat from UC Davis College of Engineering wrote in their new work. In addition, an MRI can only image so fast that the images are not fast enough to detect if the sounds match blistering or collapse.
Instead, the researchers have developed a mathematical model to accurately describe what happens in a joint as it pops. They found that the acoustics of an ankle bone are consistent with the release of the joint, the pressure on the synovial fluid increases rapidly, and the bladders partially collapse from large to small.
"Our model shows that the acoustic signature of a partially collapsing bladder in a fractured joint resembles that we experimentally observe," Suja told Live Science.
Since the paper did not include any direct observations of knuckles, it is likely to trigger further discussion. But mathematical modeling could help provide more information to solve the problem, wrote Suja and Barakat.
Original article about Live Science.