Why is cracking your back so bad?

Answer 1

Essentially what's happened is that one of your vertebrae has popped out of alignment, which causes the pain. I used to have it happen all the time with my L3 vertebrae, which is now fused like the rest of my lower spine. "Cracking" it pops it back into place, which then eases the pain as it puts the spine back into alignment. A Chiropractor does the same thing, but with more gentle movements to ease it back into place.

The risk of doing it yourself or having someone do it for you who isn't qualified is that it can weaken the disk membrane of the disk between the vertebrae that has popped out and the disks that are adjacent. If you're too rough on putting it back in, you can set yourself up for a disk herniation and worse problems down the road.

Answer 2

"Cracking" your back is not so bad at all if you are a young and healthy individual. The concern tends to be that there are some risks associated, such as fracture, sprain, strain, etc. These risks are very low when an adjustment ("cracking") is performed by a skilled professional, but when performed by yourself, or by another unskilled person, the risks increase. Even when performed by the unskilled, the risks tend to be relatively non-severe for young and healthy individuals.

It should be noted that recent research has suggested that the "cracking" sound that comes from an adjustment of a joint has no therpeutic benefit in itself. It seems that it is rather the high velocity and low amplitude stretch of proprioceptive muculature that surrounds the joint that induced the therapeutic effect. Thus, simply "cracking" your own back by twisting yourself, etc. will not result in the same benefits of a proper adjustment by a skilled professional.