Ferrokinesis Training Courses. Best Answer: cracking of joints is caused by gas build up in your joints when you so called 'crack' you release the gas when you sneeze the muscles in your lower back probably tense in a certain way that releases the gas in your joints. This isint necessarily a bad thing. There are more problems with having to much gas in your joints then not enough so if it happening naturally i wouldn't be worried about it but if you feel that it might not be normal i suggest you go see a chiropractor and tell them you think your lower back might be miss aligned and tell them it cracks often when your muscles tense. Igo Maps Uk here. They'll reposition your joints so that it will fix any needed adjustments as a fitness worker i easily recommend going to a licensed chiropractic practitioner at least once or twice a years regardless of age you never realize how much you need a good adjustment till its done. • Tell us some more • Upload in Progress • Upload failed.