Ah! Well, I believe this: Nitrogen bubbles collect in various
   parts of your body, especially where bones/tendons/muscles meet
   up. When you crack your knuckles, it releases them. Is that
   true? I don't know but that's how I visualize it. Chiropractic
   does make you feel better because that pressure can cause
   problems with nerves and such and some are hard to crack. Do I
   believe alignment of the spine is possible with chiropractic?
   Well, I think simply being AWARE of your posture because you're
   getting treatments realigns your bad HABITS and causes you to
   unconsciously begin straightening out your back, pulling your
   shoulders back, chest out, and all the things that are good for
   posture. These side-effects of the treatment will improve your
   balance and feeling of well being. Is it totally placebo? No,
   because of the nitrogen build up and the mini-stretches of the
   tendens and muscles you get in the process of realignment. So, I
   believe it can help. The theories behind chiropractic may be
   oddball 19th century stuff, but it can help in residuall ways.
   Also, it feels good to be touched by another human who has your
   best interest in mind and it's not in a relationship way. It's
   not as invasive as massage is. It "feels scientific". Plus
   insurance often covers it, and even if it doesn't, getting it
   done is cheap and fast and you feel better afterwards usually.
   So, I don't see the harm in it.