I crack mine all the time,I havent had any serious problems.The joints havent swollen,and I still have feeling in 8 of my fingers.

Arthritis Center at Providence Portland Medical Center: Likely not. I'm not saying "definitely no" because, while cracking knuckles is common, research on its effects is not. We have only a handful of studies on the subject. None shows a definite link between knuckle cracking and arthritis.

However, cracking your knuckles is neither harmless nor desirable. The arthritis connection may be an old wives' tale, but cracking your knuckles can hurt your hand in other ways, and there's no benefit to it. Some students crack their knuckles after writing a great deal, but cracking knuckles isn't a solution for writer's cramp. Instead, take a break, and bend and stretch out your fingers a few times.

Kids may develop a habit of cracking their knuckles because they like the sound. The "crack" comes because of a change in the synovial fluid, the lubricant that bathes the joints. When finger bones are suddenly stretched apart, the space between the joints widens, and an air bubble forms in the synovial fluid. The bubble quickly bursts and makes a sharp sound.