... fin­ger crack­ing causes arthri­tis?

Science Illustrated - - ASK US -

I have al­ways been told that I could de­velop arthri­tis over time, if I make my fin­gers crack. But is it re­ally true? Many peo­ple crack their fin­gers as a kind of com­pul­sive be­hav­iour, while oth­ers are dis­gusted at the pop­ping sound of the joints. Per­haps the myth that fin­ger crack­ing causes arthri­tis orig­i­nated as pro­tec­tion against the un­pleas­ant sound. No sci­en­tific stud­ies sup­port the the­ory – and it's like to be harm­less.

In a study from 2011, an Amer­i­can doc­tor, Kevin deWe­ber, com­pared X-rays of the hands of 215 el­derly peo­ple, who had ei­ther been crack­ing their fin­gers reg­u­larly for sev­eral years or had never done so. His study pro­duced no ev­i­dence of the be­hav­iour be­ing harm­ful. A not quite as sci­en­tific study was made by Amer­i­can doc­tor Don­ald Unger, who cracked the fin­gers of his left hand ev­ery day for 60 years, leav­ing the fin­gers of his right hand alone. Again, there was no ev­i­dence of the habit caus­ing arthri­tis or other ill­nesses. On the other hand, the ded­i­cated study earned him an lg No­bel Prize in medicine.

The sound of crack­ing fin­gers arises, when the fin­gers are over­stretched one way or the other such as by sub­ject­ing them to pres­sure with the other hand or by stretch­ing one­self with one's fin­gers crossed. The mo­tion pulls the fin­ger joints apart, so air mol­e­cules con­sist­ing of ni­tro­gen and car­bon diox­ide are lib­er­ated into the joint fluid with a snap. The for­ma­tion of the bub­bles pro­duce the char­ac­ter­is­tic sound. About 20 min­utes af­ter the gasses have been lib­er­ated, they are in­cor­po­rated back into the joint fluid, and the fin­gers can crack again.

ED STRETCH NOR­MAL clearly show the crack­ing joint MRI scans of the the sur­round­ing Air en­ters from bub­ble for­ma­tion. the pres­sure. tis­sue, equal­is­ing A T R E B L A F O Y IT S R E V I N U

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