A study conducted by Robert D. Boutin, MD, and Robert M. Szabo, MD, aimed to find out whether or not knuckle cracking is bad for joints.
Forty people participated in the study, 30 of which had a history of habitual knuckle cracking and 10 without. Some said they had never intentionally cracked their knuckles; others were habitual, cracking them up to 20 times a day for the past 40 years. The participants' ages ranged from 18 to 63.
Here are five things to know:
1. Dr. Boutin is a radiology professor with UC Davis Health System. Dr. Szabo is an orthopedic surgery professor with UC Davis Health System.
2. Popping knuckles is the most common kind of joint cracking, but it can also occur in the ankles, knees, back or neck.
3. To determine what causes the popping sound, a tiny ultrasound device was hovered over their joints, capturing the sound effects of knuckles being cracked. More than 400 ultrasound images were taken.
4. The UC Davis findings appear to contradict traditional explanations that the knuckle cracking sound is caused when the gas bubbles burst.
5. The researchers concluded there's no short-term harm in knuckle cracking, which appears to a contradict a 1990 study that suggested knuckle cracking can cause joint swelling and weaken the grip and "should be discouraged."