A recent study completed by the UC Davis Health system said that more than 25% of adults crack their joints. A first of its kind, the study was completed on 40 men and women between the ages of 18 and 63 years old using ultrasound to see what causes the “cracking” sound and does it damage the hand.” Ultrasound allows us to diagnose various causes of ‘clicks’ and ‘clunks’ around joints,” said study lead Robert Boutin, a UC Davis professor of radiology and specialist in musculoskeletal imaging. “But knuckle cracking looks entirely different — like fireworks exploding on the Fourth of July.” Knuckle Cracking occurs when gas bubbles form in the joints very qiuickly-faster than a blink of an eye ssays the study.

Despite the “fireworks”, examination by a hand injury- specialist found no problems in the joints of the knuckle crackers. What is interesting is the study contradicts a previous study that suggets knuckle cracking may cause joint swelling and may weaken the grip.  So why do more than 25% of adults crack their joints? Boutin says, “After a joint cracked, it had a significantly increased range of motion compared to the other joints that did not crack.” “A larger study will help determine if there are longer-term hazards or benefits of joint cracking, but we’re excited we have found a way to answer some longstanding questions about the safety of this common habit,” Boutin said.

More information about the Radiological Society of North America is at www.RSNA.org.

More information about UC Davis Health System, along with its departments of Radiology and Orthopaedic Surgery, is at www.ucdmc.ucdavis.edu.