The Habitual Cracking of the Joints: Does it Cause Arthritis?

 Joint cracking is the act of moving one’s joints in a certain way, causing a popping or cracking sound. It is a habit shared by many, a way that allows people to release anxiety and tension. This popping noise is caused by air bubbles forming in the spaces between the spaces in the joints, occurring where there is a layer of fluid at the joints separating the bones. Yet, cracking joints is a commonly misunderstood phenomenon, one stemming from an old myth many hear in their youth: popping knuckles will cause arthritis. From a young age, children were prevented from cracking their knuckles and were implanted the idea that those who popped their knuckles would have arthritis to look forward to in their futures. This old wives’ tale has been since proven false, for there was no evidence that the cracking of one’s joints caused arthritis. Unger (1998) conducted an experiment on his own left hand, which resulted in there being no proof that knuckle cracking caused arthritis. Moreover, R. Swezey and S. Swezey (1975) conducted a larger study, also resulting in data failing to provide evidence of joint cracking causing arthritis. Furthermore, a number of other studies proved that there was no connection between popping joints and arthritis, some explaining in depth the mechanism behind the cracking of one’s knuckles and the sound it made. The idea that habitually cracking one’s joints resulted in arthritis was confirmed to be a myth, thereby being more likely to cause an annoyance in the general population than arthritis.

 The popping noise caused by cracking one’s joint was determined to be caused air bubbles bursting in the synovial fluid. This occurred when joints are forced apart, causing low pressure in the joint space, which results in gases within the synovial fluid. This gas is comprised of oxygen, nitrogen, and carbon dioxide. After much debate over the theories of what caused the popping noise in the scientific world, Shepherd and Taylor (2019) stated that a “2015 real-time medical imaging study of joint spaces proved that it is the formation of the bubble that creates the noise.” Nevertheless, regardless of the concern, noisy joints did not result in arthritis, and instead, were rather common among the general population. Yet, many still believe in the idea of habitual knuckle cracking to be a cause for arthritis. However, a number of studies conclude that this was not the case, but simply a fictional myth.

Literature Review

 Unger’s (1998) experiment provided evidence that knuckle cracking did not equate to arthritis. Through his paper, he explained that, after a childhood of being informed that cracking his knuckles would cause arthritis, he decided to challenge this idea by conducting a study. In his experiment, Unger cracked the knuckles of his left hand for fifty years at least twice a day, whilst cracking the knuckles of his right hand at rare and spontaneous times. In the end, the results indicated that there were no differences between the left and right hand, as well as a distinct lack of arthritis. This provided proof that knuckle cracking did not lead to arthritis, nor was there a relationship between the two, as demonstrated by a fifty-year study done by one person.

 Moreover, a larger study done also came to the same conclusion. In this study, a survey involving twenty-eight patients from a Jewish home for the aged who recalled cracking their knuckles. The purpose of this study was to detect bony enlargement and degenerative arthritis in the metacarpal-phalangeal (MCP) joints, and those who had popped their knuckles were examined clinically and by x-ray. Thus, radiographically identifiable osteophytes were required to diagnose MSP degenerative joint disease (DJD). In their experiment, the results demonstrated that only one patient with knuckle cracking tendencies showed MCP DJD, while fourteen other poppers showed no changes. As well, five other patients had MCP osteophytes, despite being non-knuckle crackers, while eight patients, who did not pop their knuckles, had normal MCP joints. By the end of the study, the results indicated that there had been no positive correlation between the knuckle cracker patients and the degenerative changes in their MPC joint, thereby demonstrating that habitual knuckle cracking did not lead to arthritis, as shown in the survey of geriatric patients done (R. Swezey et al’s, 1975).

 A study similar to R. Swezey et al’s was also published in the 1990’s. In this study, the relationship between knuckle cracking to hand function was examined, involving 300 consecutive patients, all of whom were 45 years old or above. These patients were assessed for arthritis and knuckle cracking habits, as well as had no evidence of neuromuscular, inflammatory or malignant disease. To conduct this study, the 300 patients were fully examined and resulted in significant difference between those who cracked their knuckles and those who did not. In the end, hand swelling occurred more often in knuckle crackers than in the other group, thereby proving that cracking one’s knuckles may relate to decreased hand function. Thus, the results of this study proved that habitual knuckle cracking did not have a relationship with arthritis, but also suggested that it may relate to having a lower grip strength and hand swelling (Castellanos and Axelrod, 1990).

Discussion

 Through this paper, the aim of this research was to provide evidence of the relationship between cracking one’s joints and arthritis. Overall, the general consensus of the studies conducted over the years appears to conclude that there is no correlation between cracking one’s joints and arthritis. Thus, it appears that it is simply a myth that has no evidence to support its claim, after several studies comparing the frequency of hand arthritis among those who did and did not crack their knuckles rejected the idea. Certainly, although habitual knuckle cracking may result in a decrease in hand function, it does not have a positive relationship with arthritis. Instead, joint cracking was examined to perhaps result in a decrease in hand function, as well as abnormalities in the joint structures, if they were accompanied by pain and swelling. Thus, cracking one’s joints, if done occasionally, was not harmful, nor cause damage to the joint (Bradford, 2014).

Conclusion

 In conclusion, the habitual cracking of the joints resulting in arthritis was proven to be false. Rather, it was simply a myth that had no evidential support, other than the words of another. Multiple studies had proven this, including the fifty-year experiment of Unger and a larger study done by R. Swezey et al, as well as other studies and papers, all of which conclude that there is no relationship between popping one’s joints and arthritis. Truly, through the numerous studies and papers done, the old wives’ tale regarding knuckle cracking and arthritis was disregarded, explaining that, regardless of one’s knuckle cracking habits, one would not be more likely to get arthritis than the other. And so, future research would become more focused on the effects of joint cracking on the joints itself, as well as the mechanism of the loud popping noise. Thus, the idea behind the habitual cracking of the joints caused arthritis was investigated to be fictional, for it appears to be less likely to cause arthritis problems than it is to result in general public disturbance.

References

• Bradford, A. (2014, September 20). Why Knuckles Crack and Joints Creak. Retrieved from https://www.livescience.com/4125-knuckles-crack-joints-creak.html
• Castellanos, J., & Axelrod, D. (1990). Effect of habitual knuckle cracking on hand function. Annals of the rheumatic diseases, 49(5), 308–309. doi:10.1136/ard.49.5.308
• Greenhalgh, T. (2019, April 4). Does Cracking Your Knuckles Cause Arthritis? Retrieved from https://www.rheumatologyadvisor.com/home/topics/osteoarthritis/is-knuckle-cracking-bad-can-it-lead-to-arthritis/
• Nichols, H. (2017, June 21). Knuckles and joints: Does cracking knuckles cause arthritis? Retrieved from https://www.medicalnewstoday.com/articles/259603.php
• Shepherd, R., & Taylor, A. (2019, March 12). Here’s Why Joints Crack And Pop, And What It Really Means For Your Poor Old Body. Retrieved from https://www.sciencealert.com/here-s-why-joints-really-pop-and-what-it-means-for-your-poor-old-body
• Shmerling, R. H. (2018, May 6). Knuckle cracking: Annoying and harmful, or just annoying? Retrieved from https://www.health.harvard.edu/blog/knuckle-cracking-annoying-and-harmful-or-just-annoying-2018051413797
• Swezey, R. L., & Swezey, S. E. (1975). The consequences of habitual knuckle cracking. The Western journal of medicine, 122(5), 377–379.
• Unger, D. L. (1998). Does knuckle cracking lead to arthritis of the fingers? Arthritis & Rheumatism, 41(5), 949-950. doi:10.1002/1529-0131(199805)41:5<949::AID-ART36>3.0.CO;2-3
• Unsworth, A., Dowson, D., & Wright, V. (1971). ‘Cracking joints’. A bioengineering study of cavitation in the metacarpophalangeal joint. Annals of the rheumatic diseases, 30(4), 348–358. doi:10.1136/ard.30.4.348