I heard from somewhere that it releases oxygen bubbles (for your knuckles.) I don't know if that happens to other parts of your body.. But why people have a habit or whatever of cracking their neck, back and knuckles, is because the person either doesn't feel they can move properly or other reasons.
Cracking joints is the action of moving joints to produce a sharp cracking or popping sound. The most common form of this occurs during deliberate knuckle-cracking. It is possible to crack many other joints, such as those between the back and neck vertebrae, hips, wrists, elbows, shoulders, toes, ankles, knees, jaws, and the Achilles tendon area. Some people worry that "cracking your knuckles gives you arthritis" but that is not supported by any factual evidence. A study concluded that there was no increased likelihood of arthritis of the hand, but habitual knuckle-crackers were more likely to have hand swelling and 25% lower grip strength. I hope that this info helps.
When you crack your joints it feels good because you are letting out tension.An example is you havent moved for hours.Even though it feels good I would not recommend doing it.It gives you a higher chance of Arthritis.
2 years ago
Last edited at 9:59AM on 8/14/2011
When you crack your neck and back, it often feels good afterwards, especially if there was a great deal of tension or pain prior. The reason it feels good to crack your neck and back is because pressure is being relieved. Just as when any of your joints crack, gases are being released from within the synovial membranes. This release can cause a temporary relief of pressure or pain. In most cases though, the pressure or pain will return.
Many people can forcibly crack their joints, even their neck and back. In some cases, such as when performing stretching or yoga exercises, natural movement may also cracking. You might also visit a chiropractor who will crack your neck and back through a series of manipulations. While these manipulations can relieve pain and pressure in the back or neck, there are some studies that indicate cracking the neck may be linked to an increased risk of stroke.
If you forcibly crack your neck and back frequently, especially as a means to relieve pressure and pain, you might consider visiting a chiropractor or a physician. In some cases, chronic neck cracking can lead to loss of elasticity in the ligaments, which forces the muscles to work harder and tire easier. This happens when the joints are forced beyond normal range of motion and the ligaments stretch out over time. When they do not return to normal, this causes a condition known as hypermobility.
When you crack your neck and back, you should avoid forcibly stretching your joints beyond normal range of motion. Since there is some research that indicates cracking joints can lead to arthritis, it may be best to avoid forceful cracking. If you experience frequent neck and back pain, which may or may not be relieved when you crack your neck and back, you should visit a doctor. There could be underlying causes, including injury or a degenerative condition.