One of our meetings was interrupted by someone cracking their knuckles and we wondered what makes the popping sound.
The Science Part
When you crack your knuckles, you’re not actually cracking anything.
The popping sound that can be heard is caused by gas escaping the cavity between the two pieces of bone.
This was confirmed in 2015 when the University of Alberta conducted a study of forty people. The people conducting the study had participants crack their knuckles under an ultrasound machine and were shocked when they studied the results. Through careful analysis they saw mini explosions erupt from between the two halves of the joint. This study once and for all put to rest the misconception that the sound made when you crack your knuckles is made by the bones cracking together.
People don’t like it when you crack your knuckles as it sounds like to pieces of bone cracking together.
Whilst the long term effects of cracking your knuckles are still being studied, increasing evidence is refuting the idea that the habit can cause arthritis. Even though LearnPlay doesn’t promote cracking your knuckles, evidence of long term damage is becoming scarce.