Knuckle Popping – Is it Good or Bad?

We’ve all heard it said, “Keep popping your knuckles and you’ll get arthritis”, but is it true?  Before we get into the research, let’s look at what causes the “pop”.

Popping of a joint happens when the joint is stretched to a point that a vacuum or suction forms inside the joint.  Most of our body’s joints are lubricated and nourished by fluid within the joint, and this fluid is produced and kept in the joint by a capsule or sack that surrounds the joint.  As the joint and joint capsule are stretched, this creates a vacuum inside the joint.  As suction increases and the pressure drops, gases that dissolve in the joint fluid form bubbles.  These bubbles are then popped by fluid rushing into the increasing space between the joint surfaces as they continue to stretch.  This end result is the characteristic, audible pop or crack that causes so many to cringe and scowl, but it also increases joint space and relieves stiff joints.

Many researchers have studied the correlation between popping knuckles and arthritis and have failed to find a connection.  In all of the studies, no statistically relevant connection has been found between the two, but this does not mean all is well.

Generally speaking, if the stretch that leads to popping is performed within the normal range of motion of a joint, there is very little risk of injury to the joint.  But, like any stretch, if performed too aggressively, it can sometimes lead to hyper-flexibility or even injury.  Rare cases of ligament tears caused by “vigorous” or “devious” knuckle popping have been reported. 

One research study found older knuckle crackers were more likely to have hand swelling and reduced grip strength than their age matched peers, but frequency of arthritis was equal between the groups.  This study also found that knuckle crackers were more likely to have been manual laborers and also frequently drink and smoke; because of this, they could not establish a causal relationship to knuckle cracking, therefore describe the relationship as an association.

So what is the final verdict? While research has clearly debunked the myth of knuckle cracking as a cause of arthritis of the hands, questions still remain for older adults as to its relationship with other hand symptoms.  If you feel the need to keep cracking, keep it to a light stretch, and you should be okay.