Why Does My Body Crack So Much When I Move?

If your shoulders pop when you reach overhead or your knees crack when you squat down, you’re not alone. Those little clicks and cracks can be oddly satisfying or slightly concerning. So what’s actually going on when your body sounds like a bowl of Rice Krispies?

The Science Behind the “Crack”

Most of the time, those sounds are called cavitations- tiny gas bubbles forming and collapsing inside your joint fluid (synovial fluid). Not bones grinding or something “out of place”.

When you move or stretch, the pressure in the joint changes, and gases that were dissolved in the joint fluid form a bubble and then dissolve again. This process is known as tribonucleation, and is the mechanism behind the "pop" when you crack your knuckles.

Fun fact: after a joint “pops,” you usually can’t make it crack again right away. That’s because it takes time for the gases to re-dissolve into the fluid before another bubble can form (about 20 minutes or so).

Different Kinds of Noises You Might Hear

There are a few different names for those noisy clicks and pops:

Cavitation (aka tribonucleation): The harmless “pop” from gas bubble formation and re-dissolving inside the joint.
Crepitus: A broader term for crackling, grinding, or grating sounds-sometimes normal, sometimes a sign of wear or inflammation.
Clicking or popping: Everyday noises from joints or tendons gliding over bone.
Snapping: A sharper sound, often from a tendon flicking across a bony surface.
Grinding or grating: A rougher sensation that can happen when joint surfaces rub together- worth checking if it’s consistent or painful.

When It’s Harmless (and When It’s Not)

Totally normal:

Occasional popping without pain
Happens after being still for a while
Doesn’t limit your movement

Worth checking out:

Noises that are paired with pain, swelling, or stiffness
One joint that pops every time you move it
Clicking that comes with a catching or “stuck” feeling

Those can be signs of joint instability or injury to the joint and its supporting soft tissue structures, like the cartilage (e.g. meniscus), joint capsule, or surrounding ligaments.

Why You Don’t Need to Chase the Pop

A lot of people associate “good” chiropractic care with that satisfying crack, but that sound doesn’t mean something’s been “fixed.”

What matters most is how well your body moves and feels afterward. Through soft tissue work, mobility exercises, and gentle adjustments (when needed), and manual therapy helps to restore healthy joint stability and motion, with or without the noise.

The Bottom Line

Cracks and pops are usually just your body’s natural response to movement and pressure changes. But if the sounds come with pain, catching, or stiffness, it could indicate joint instability or injury to the joint and its supporting soft tissue structures. In those cases, the focus should be on restoring joint stability, strengthening the muscles that support the joint, and promoting good biomechanics to reduce excess stress in the area, not chasing the noise itself.