Ever since I was a little kid, I have cracked my knuckles as a nervous habit. I’m not a nail biter, nor a hair twister; I push down on the joints of my fingers until I hear that satisfying “popping” sound that calms my nerves. Because of this habit, I have been told by everyone I know countless times that I will develop large knuckles or arthritis in my fingers later on in life. After several years of cracking my knuckles, I have yet to develop swollen fingers or any pain in my joints which leaves me to question whether there is a correlation between cracking your joints and developing arthritis.
The “popping” sound we hear when we crack our knuckles comes from the bursting of gas bubbles located in the synovial fluid which surrounds our joints. This occurs when we press on the joints or pull and stretch the bones apart (Harvard Health Publications). Research shows that anywhere between 25 and 54 percent of the population cracks their knuckles, the habit being more common among males than females. Because of this phenomenon, several studies have been done to find out whether this habit creates any risks to our bodies (Medical News Today).
One experiment was published in 1998 by Dr. Donald Unger. He reported that he used his right hand as the control while he cracked the knuckles on his left hand twice a day for 50 years. It is estimated that his left knuckles were cracked up to 36,500 times. After the 50 years it was found that neither hand had arthritis nor were there any significant differences between the two hands. This study concluded that knuckle cracking did not cause arthritis (Medical New Today).
However, while cracking your knuckles may not lead to arthritis in your hands, it may correlate with swollen fingers and a weak hand grip. Further studies conclude that 84 percent of chronic knuckle crackers develop swollen joints later on in life compared to a mear 6 percent of non- crackers (Samuel Merritt). Now, does this mean that cracking your knuckles directly causes swollen joints and decreased hand strength? Or is there another variable that creates these harmful effects? Perhaps many knuckle crackers are often people who use their hands a lot such as manual laborers, typists, writers, or painters. This would therefore mean they feel the need to stretch or “relieve” their fingers more often and so, they crack their knuckles. This wouldn’t mean that the knuckle cracking directly causes the swelling or weakness, it would be due to the confounding variable such as their occupations.
Another idea to consider would be the idea of reverse causation meaning that arthritis and swelling of the joints causes people to crack their knuckles. This idea obviously makes no sense and is impossible therefore, it can be ruled out. As always, chance is a possibility. It may be a complete coincidence that people who crack their knuckles do or don’t develop arthritis or swollen joints.
In conclusion, studies have reported that cracking your joints does not lead to the development of arthritis. It is still undecided whether it causes swelling and a weakness of grip in the hands but there is a correlation between the two. For now, I would say that cracking your knuckles creates no real harm to your body and may just be an annoyance to the people around you so, continue to “pop” away.