Why is it that some joints have a “cooldown” to be cracked and others have none? What’s the difference?


There’s always discourse regarding what cracking joints are. There’s synovial fluid, tendons slipping, arthritis, crepitus. It’s all very confusing. and help me understand!

In: 1

We don’t really know why joints crack. As you allude to, the leading theory is that it’s related to bubbles forming/popping in your synovial fluid — the liquid around your joints.

When you crack a joint and create/pop that bubble, it then takes a bit of time for the fluid to re-settle/allow a bubble to form again. That is the refractory period or “cooldown” you’re referring to.

**_All joint cracks of this type have a refractory period._** It may not be very long for certain joints, depending on your particular anatomy. But there is always some sort of refractory period.

If you can move a joint to create a constant, recurring cracking noise with no refractory period — **that’s a different type of crack, and it’s probably bad for you.**

For example, I can get my wrist to repeatedly make a cracking sound… but that’s because I’m hypermobile and my wrist bones are basically scraping together. That’s not a synovial fluid, bubbly, relieving, safe crack. That’s the sound of my joint doing something it’s not supposed to.

On the other hand, I can also “normally” crack my wrist, which provides that relieving “pop” feeling and does have a refractory period.