Whether you crack your fingers on purpose or by accident, you can “crack” your back the same way you crack your knuckles and that doesn’t mean you’re fracturing or cracking bones or cartilage.
The sound that you hear when you crack your bones, indicates the shifting of spinal joints. That cracking sound that people hear is the release of gas bubbles within the spinal joints.
When the spine is out of alignment, the joints can swell and fill with bubbles that may pop when you move certain ways. The gas pockets of nitrogen, oxygen, and carbon dioxide in the joint fluid reaccumulate over time, which is why we can’t usually crack the same joint several times in a row.
The back on its part gets to crack after you’ve been stuck in the same position for a long time; especially if you’re hunched or slumped.
While back cracking can occur accidentally, some people do it intentionally, to relieve discomfort caused by misalignment. Sometimes people will twist or move in a way they know will pop their spinal joints simply because it feels good.
Researchers found in a 2011 study that people associate the sound of releasing joints with relief. Some chiropractors claim that cracking your back can release feel-good substances called endorphins.
Irrespective of how good it may feel to crack your back, most experts agree that doing it frequently isn’t worth the temporary relief. Constantly doing so could make you end up with chronic back pain from damaged discs and nerves.
The repeated twisting may cause excessive wear on your spinal joints. The most important thing is that popping your back may not address the root of your spinal issues—especially since your actions could be affecting the wrong joints.
A lot of people who crack their backs daily actually have spinal subluxation; a condition where their vertebrae are misaligned. Cracking your back only moves the joints that are compensating for the subluxation which will make the primary problem worse, or wear down the compensating joints.
While routine back cracking could do more harm than good, the occasional pop such as the ones you might experience after a long day of sitting—is no cause for concern.
If you are moving your spine through normal ranges of motion without the use of any additional force, and you happen to hear that cracking sound, this is considered safe.
Anything outside of that, any introduction of force to a spinal joint should be left for the chiropractors.