Get Cracking?

Medical Insurance For Expats In Singapore GET A QUOTE


Many people crack their knuckles and take this habit for granted. Indeed, one feels relief after this process, but what happens with our joints at that moment? Moreover, why does cracking our knuckles feel good? Tim Maiden of The Foot Practice is going to shed some light on these matters.


Knuckle, from the Middle English ‘knokel’, is the part of one’s finger at a joint where the bone is near the surface. Anatomically speaking, the knuckles are formed of the metacarpophalangeal (MCP) and interphalangeal (IP) joints of the finger. The knuckles at the base of the fingers are also known as the 1st or major knuckles whereas the knuckles at the mid-fingers are known as the 2nd and 3rd, or minor, knuckles. Besides the knuckles, people crack their neck, lower backs, hips, ankles and toes. Any joint can be “cracked,” either by a specialist or at home.


The cracking sound is produced because at the tips of bones at these joints is the articular cartilage that is covered by a “joint capsule” with synovial fluid. This fluid serves as a lubricant for the articulation, protecting the cartilage and tissues. Also, synovial fluid is nourishing the cells that maintain the joint cartilage. Gasses like oxygen, nitrogen and carbon dioxide are found in the dissolved form in the synovial fluid. That is why, when one pops or cracks a joint, he tightens the joint capsule. Gas is quickly released forming bubbles. To crack the same knuckle again, one has to wait about 20 minutes until the gases return to the synovial fluid.


Doctors used to think that the cracking sound was the result of the bubbles pop in the synovial fluid. However, this year, they found out that the sound arisen from knuckle cracking was the outcome of a cavity forming in the joints. Nothing is being broken or damaged. In fact, the cracking itself takes less than 310 milliseconds.


So, the main process involves the pulling of two bones in the joint farther and farther one from each other, until we hear the crack, which signifies that the bones smashed together. The joints after cracking remain apart, forming a space called “void”. This dark spot persists after the cracking sound was heard.


Some people crack their knuckles out of pleasure, feeling a physical relief, or looseness and enhanced mobility for a short period.  Others do that out of habit, just like some whirl their hair or wiggle their foot. However, is this habit good or bad? Is knuckle cracking causing arthritis?


According to a study, people who crack their knuckles are not likely to develop hand arthritis. However, their hands can swell, and they can have lower grip strength. This means that joint cracking is not correlated with arthritis, but is correlated with the displacement of tendons and injury of ligaments.


Dr. Donald Unger published a fascinating study regarding this matter in 1998, entitled “Does knuckle cracking lead to arthritis of the fingers?” to the editors of Arthritis and Rheumatism, the world’s first rheumatology journal.


In his experiment, which lasted 50 years, Dr. Unger had been cracking the knuckles of his left hand at least twice per day whereas he never cracked the knuckles on his right hand, which was used as a control. Overall, the joints on the left hand were cracked at least 36,500 times whilst those on the right hand were cracked rarely and unconsciously.


Unger wrote, “During the author’s childhood, various renowned authorities (his mother, several aunts and his mother-in-law) informed him that cracking his knuckles would lead to arthritis of the fingers”. It took him half-century “to test the accuracy of this hypothesis”.


Subsequently, after fifty years, Unger reported: “There was no arthritis in either hand and no apparent differences between the two hands”. He concluded, “There is no apparent relationship between knuckle cracking and the subsequent development of arthritis of the fingers”. For this research, Dr. Unger received the 2009 Ig Nobel Prize for Medicine.


As a result to Unger’s study, Dr. Robert Swezey reported that his 1975 research also did not prove the relationship between the knuckle cracking and arthritis. The 28 partakers of the study were residents of a Jewish care home in Los Angeles. They were divided into two groups: people that used to crack their knuckles, and those who did not. Those who used to do that were not endangered of developing osteoarthritis in their hands later on.


Recently, investigators at the Uniformed Services University of the Health Sciences decided to research the connection between knuckle cracking with arthritis. At the study partook 214 people, 20% of them cracked they knuckles constantly. Out of these 20%, 18.1% had hand arthritis compared to 21.5% participants that did not pop their joints.


Some recent studies have proven that the chances of gaining arthritis are equal for both categories. The studies also showed that arthritis is not the only concern for people that use to crack their joints. Doesn’t matter what causes joint popping and cracking, the sounds that result from this action does not require treatment.


None of the chronic health issues, the so-called long-term sequelae, are connected with the cracking sounds, so there is not any scientific foundation in saying that cracking knuckles lead to arthritis. Also, there are no methods to eliminate these noises once they appeared. Overall, the cracking and popping of joints are normal, and one should not be concerned about that.


If along with the sound of joint cracking appears pain it is time to worry. Joint tumefaction is not normal as well, and must be treated by a specialist. If joint popping and cracking do not go smoothly, and the joints lock up, this may indicate a problem that needs a specialist’s attention. It is a matter of great importance to seek treatment if something of the following happens: joint swelling, limited joint motion or unsmooth joint movement


The Foot Practice


The Foot Practice treat a broad range of conditions from sports injuries, children’s foot issues, to diabetes and everyday foot and ankle concerns.
Brought to you by Expat Insurance

Medical Insurance For Expats In Singapore GET A QUOTE

Having evaluated the numerous products available in the Singapore market, Expat Insurance has identified those that offer the broadest coverage, catering to the unique needs of expatriates.

We provide professional insurance advice on a complete portfolio of products for Individuals and Companies including: Medical and Health Insurance,Home and Contents Insurance, Travel Insurance, Motor, Personal Liability Protection, Corporate Employee Benefits Programmes and Insurance.

Feel free to reach out to the team on 6401 9201 or [email protected]. Our job is to take great care of you and your family to ensure you get the best value for money coverage available.

Authored By John Ntatsopoulos


Over the course of his 34 years career, our CEO, John, have worked predominately in the area of insurance and financial services across major APAC…


We'd love to hear from you!
Leave your contact details below with a
little note telling us how we can help you.

We've got you covered!

Corporate enquiries:
+65 6439 8026
[email protected]

Individual enquiries:
+65 6401 9201
+65 3110 3220
[email protected]