What is the Crack?
What do you think the ‘Crack’ is when you have an adjustment? Maybe you think it’s the ‘cracking’ of bones or the popping of a bubble? Is it the same thing happening when you crack your knuckles? Or is that entirely different? Let me tell you…
Let’s start where the cracking takes place:
Each joint is, essentially, the end of 2 bones. These bones are held together by ligaments, which help to form the ‘Capsule’ surrounding the whole of the joint. This stops the joint from moving too far.
This capsule is filled with fluid (“Synovial Fluid”). The main task of this fluid is to reduce the amount of friction in the joint. And, of course, the less friction you have the longer the joint can ‘work’ for. It also carries nutrients to the parts of the joint that don’t have a blood supply. (One reason why you need to keep moving even with arthritis!)
Then, dissolved in the synovial fluid are gases. And like the atmosphere around us, it is mostly Nitrogen.
Now, you might think that when a joint ‘pops’ it’s bubbles of that gas popping – but you’d be mistaken (just as I once was). It is, in fact, the gas being pulled out of the solution and forming bubbles!
And as gas takes up more space than a liquid, it’s a sign that the joint has more ‘space’ inside of it. In ‘technical terms: the joint has gone through it’s “Full Range of Motion”. Which is what the adjustment is aiming to achieve.
If you’ve ever cracked your knuckles, you’ll have noticed that you can only do it once. This is because it takes about 20 minutes for those gases to redissolve. (I love facts like that, ones that you kinda already know, and yet don’t.)
As the Irish say “What a Craic!”