Short Stuff: Knuckle Cracking | STUFF YOU SHOULD KNOW

Ajouté : 2026-05-30

[00:00:04]Hey, and welcome to the short stuff.

[00:00:05]Josh, Chuck, Cherry sitting in for Dave.

[00:00:08]So, this is short stuff. Uh, Chuck, I have a question for you.

[00:00:14]Are you cracking your knuckles right now?

[00:00:16]>> I am. Did you hear that?

[00:00:17]>> Yeah. I That wasn't like a like a Foley effect.

[00:00:21]>> No, I was cracking my knuckles. I'm a knuckle cracker. I don't do it I did it a lot when I was a kid. Uh, but I I still do it some.

[00:00:30]>> Uh, this is what my knuckles sound like when I crack them.

[00:00:39]That's it. Um, the uh Yeah, I I can't do it again because I have to wait 20 to 30 minutes for the air bubbles to come back and cavitate once more.

[00:00:49]>> Yeah. Well, well, tell everybody what's going on here. or what I know there was a lot of you know when you were young everyone was like it'll give you arthritis and it's your your bones grinding together and that's what cracking your knuckles is and that can't be good for you.

[00:01:02]>> Yes. If your bones ground together you would not be able to think of anything else but your bones grinding together because you would be in so much pain that um you would know your bones are grind together. That's not what cracking your knuckles is. It turns out instead it has everything to do with the the space and the area around where your bones come together. Your bones don't actually come together.

[00:01:25]>> That's right. Uh where there's a joint that is where two bones meet, but they're separate and they're held together by ligaments and connective tissues and all that stuff. But there's also some a very other key ingredient in there. It's called uh synovial fluid.

[00:01:41]It's a thick clear liquid that kind of encases that area. Right.

[00:01:45]Yeah. Uh, it's it's thick. It tastes just like orange crush.

[00:01:50]>> Crush, >> surprisingly. And when you when you pop your knuckle, what you're doing is stretching or bending the the ligaments and connective tissues and the cyanovial fluid there too. Right? So when you do that that capsule is what it's called the connective tissue capsule that includes the sinovial fluid it gets stretched which increases its volume and then suddenly the pressure inside the capsule in that sinovial fluid um it goes down it decreases in pressure which means that all these gases that used to just be part of the solution now are part of the problem I mean now turn into bubbles >> that's right uh so they become you know they form those bubbles Uh, and if you stretch that joint far enough, like, you know, trying to crack your knuckles, the pressure in the capsule goes so low that it just pops those bubbles and that's the popping sound that we're hearing.

[00:02:41]>> There you go. Not your bones rubbing together. Okay. I want you to go to recess and tell your friends that is not your bones rubbing together.

[00:02:50]>> Yeah. Uh, and then the cavitation you mentioned earlier. I think before we break, we should just clear that up. You said 20 to 30 minutes. That is how long it takes for that gas to redesolve into that joint fluid and uh cavitation is is possible again.

[00:03:07]>> Yeah.

[00:03:08]>> Go watch cavitate my knuckles.

[00:03:10]>> Yeah, exactly.

[00:03:13]>> Oh, I just did one again.

[00:03:15]>> Uh okay, I say we take a little break and come back and talk about how we know that cracking your knuckles doesn't give you arthritis.

[00:03:22]>> All right, we'll be right back.

[00:03:27]Stuff we learn from Josh and Chuck.

[00:03:32]Stuff you should know.

[00:03:54]Chuck, I know we've talked about this guy before. Dr. Donalder. I think we did a video about him.

[00:04:00]>> Yeah.

[00:04:00]>> But he, you know what? I'll bet we talked about him in the Ignable Prize >> episode because he won an Ignable for this.

[00:04:08]>> But essentially, he conducted an experiment for 60 years because he wanted to prove his mother wrong >> and he only cracked the knuckles on, I think, his left hand. Never cracked them on his right hand.

[00:04:20]>> That's crazy. And then after 60 years, he finally said, "Okay, it's time." And he x-rayed his hands.

[00:04:26]>> Yeah.

[00:04:28]If he didn't have the compulsion to crack his knuckles, I could see how this happened. But if you are a knuckle cracker, you're kind of you feel compelled to do it. So it I can't imagine what it would have taken to not crack the knuckles on one hand for that many years. It must have been uh really tough.

[00:04:45]>> Yeah, sure.

[00:04:46]>> That's my guess. So yeah, he did this over his lifetime. uh he x-rayed himself on the reggg and eventually decades later came to the conclusion that he doesn't have any arthritic difference in his hands. Case closed.

[00:05:01]>> He had NAD, no arthritic difference.

[00:05:05]>> That's right.

[00:05:06]>> That's not to say though that even if you don't get arthritis from cracking your knuckles, it's another thing you can tell your friends at recess. Do they even have recess anymore?

[00:05:14]>> I guess maybe hourlong screen time. No, they have recess.

[00:05:19]>> Okay, great. Um, there is damage that you can do from cracking your knuckles habitually.

[00:05:26]Uh, there was a guy named Raymond Broer and he examined 300 people who cracked their knuckles to look at what their joints looked like and compared to the control group, no difference with arthritis again. Um, but there was other damage like soft tissue damage to that the ligaments and the sinovial fluid capsule. Um and that they had a decrease in grip strength. So if you crack your knuckles a lot, like don't even think about holding a glass of water with just one hand.

[00:05:56]>> Yeah. Which, you know, as you age, grip strength is important. So it it's definitely not a harmless thing. Uh there's some other possible side effects. Um something called ligament laxity.

[00:06:06]>> Yes.

[00:06:07]>> Uh which is basically looseness. So over time, if you're just doing this a lot, um that that's what leads to the reduced grip strength and and sometimes sort of overall hand function.

[00:06:17]>> Yeah.

[00:06:17]>> Uh I think in rare cases, if you're if you have a really weird method or forceful method or you're a little too aggressive with it, um you can get some soft tissue swelling around the knuckles and the joint.

[00:06:30]>> Yeah. And you can just straight up injure yourself if you you can like um dislocate a joint. You can injure your tendons.

[00:06:37]Uh, and even if you don't straight up injure yourself, just habitually cracking your knuckles over time, the stretching of the ligaments can it, like you said, the grip strengthening um is a is a big deal just even without cracking your knuckles. So um it also happens in pitchers too um major league pitchers.

[00:06:56]Imagine um minor league pitchers too.

[00:06:59]But over the years, just throwing over and over and over again, they're stretching those ligaments suddenly, violently, basically, which is kind of what you're doing when you crack your knuckles, they're just doing it with different ligaments. But that is why Oral Hershiser's right arm just dangles uselessly at his side because it's been ruined. He ruined it pitching.

[00:07:19]>> Yeah. I mean, I know you're kind of kidding, but sad but true. like especially these days there's been uh more and more instances of >> um Tommy John surgery being required because pitchers are throwing harder and harder and if you're not, you know, able to get it near 100 miles an hour these days, you're not going to have much of a chance. So, it's a real problem in baseball.

[00:07:41]>> Um >> that was a real bring down from my joke.

[00:07:44]>> Yeah.

[00:07:46]I just love that you love saying Earl Hersheiser.

[00:07:48]>> Sure. Who else to say?

[00:07:51]>> Uh boy, he was great. Yeah.

[00:07:53]>> Um, there was a study in 1990 that confirmed the grip strength thing. I think they studied 74 people who regularly cracked their knuckles and their average grip strength was definitely lower. Uh, and they had more instances of hand swelling than the 226 people who did not crack. Uh, and another interesting thing is they found that in another study that if you're a habitual knuckle knuckle cracker, um, you are more likely to be a manual laborer, uh, more likely to bite your nails as I do.

[00:08:23]>> Uh, smoke cigarettes, which I don't, and drink alcohol, which I do.

[00:08:28]>> Yeah. So, you're, you know, three for five.

[00:08:32]>> Yeah. I don't manual labor, so shouldn't count that one. So, um, there is some benefits to actually cracking your knuckles though, too. We're not just hating on cracking your knuckles. Um, there's something called the GGI tendon organs, not the Golgi apparatus. That's a different different episode alto together. Um, the Golgi tendon organs sense muscle tension. And when you crack your your knuckles, you're actually relieving some muscle tension. So, the the muscles around the joints when you crack them get relaxed. So you can feel like you know your your hands feel pretty mellow after cracking your knuckles. I saw it described as yoga for your knuckles.

[00:09:13]>> Oh, interesting.

[00:09:14]>> Yeah, I thought so, too.

[00:09:16]>> Is that like getting your back cracked or something?

[00:09:18]>> Basically. Yeah, but for your knuckles.

[00:09:20]>> Yeah. Uh we found one more thing. You know, like I'm at the age where, you know, if I kneel down to get something, uh you're going to hear a couple a snap, crackle, and a pop maybe coming from some part of my body. Do you make an involuntary sound too when you're getting up? I do.

[00:09:36]>> Oh. Oh, yeah. Like, oh god, here we go.

[00:09:39]Or something like that.

[00:09:39]>> Yeah. Like you can't not do it.

[00:09:41]>> Yeah, for sure. And when I walk downstairs, um my right ankle like on every step just goes pop.

[00:09:51]>> So, those things happen. Uh I I don't think anyone knows exactly where that comes from. Uh there's speculation it could be just like, you know, if it's your knee, it it may be your kneecap rubbing on the bones or something like that or maybe a tendon sliding over uh a bumpy surface or something like that. So I don't think it's anything to be alarmed about.

[00:10:11]>> It is alarming though, for sure.

[00:10:13]>> Yeah, because it comes with age. So every new pain and sound is like, "Huh, that didn't happen a few years ago."

[00:10:18]>> Exactly. I should go sit down for a while.

[00:10:21]>> Right.

[00:10:22]>> Uh you got anything else for short stuff guy?

[00:10:25]>> I got nothing else. So, I can't crack my knuckles. So, uh Oh, wait. There went one.

[00:10:30]>> Recapitated.

[00:10:31]>> So, what does that mean, though?

[00:10:33]>> I think that means short stuff is out.

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