h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Why does it happen? For example, you stretch your arm and your elbow clicks. Sometimes it hurts too!

Also, my shoulderblade clicks too when I rotate my right arm backwards, but I think that might be a cartilage thing.

Any of you biology types know why?

I think it's something to do with fluid getting trapped in the joint.

The clicking noise you hear is actually the tendon attached to the joint snapping back into place. Or so I've always been led to believe

If it's the tendon clicking, why does it not click again for a few minutes after it's clicked once? Sounds more like a build up of something to me.

Joint clicking is usually due to flicking of ligaments or synovium (the inner membrane of the joint capsule) from one position to another. In a healty joint there is a sort of vaccum which are replaced by gas bubbles and those gas bubbles makes the "click".

A good explanation can be found here http://www.studentbmj.com/back_issues/1097/data/1097ed2.htm

yeah, a labmate told me yesterday that the vacuum created causes CO2 to leave the blood/body fluids. This CO2 are buble that case the click.

I feel terrified of joints clicking now!

But is this unhealthy?

Some people can constantly 'click' their knuckles. I can't. But my lower back often 'clicks' when I am doing yoga. In fact, I often hear other people's backs 'click' during yoga class. The feeling after a 'click' is often one of relief.


az

>>indicates that old age begins around the age of 42

From the article:

"The real reason for not clicking your metacarpophalangeal joints is that it is intensely irritating to people who cannot do it."




az

I don't think there's any danger from clicking joints (apart from vengeful colleages finally snapping and killing you) and I'm almost enirely sure that he old "you get arthritis if you click" is a myth.

Things I can click.

Little knuckles on fingers
medium knuckles on fingers
thumbs
knuckles where fingers meet hand
Wrists
Elbows
Shoulders
Jaw
Neck
Back
Hip
Knees
Ankles
toes

Why is it that paticular joints seem to 'need clicking'? It seems akin to 'restless legs' - my left ankle often has to be rotated & clicked for me to feel comfortable, whereas no problems with the right one.

For some reason my right big toe is clickable just by bending it and straightening it again. It does it about five times in a row and then stops until I rest it for a while...

I used to be able to click my knuckles but it just hurts if I try now.

I used to be able to make farting noises by putting my left hand under the opposing armpit and waggling my right arm like a wing. But that's another story...

Oh the joys of a long winter evening

Does anyone else do their knuckles in compression? I find that if I compress my fingers into my palm I can get the same effect, except it is more of a 'crump' than a click. But as az says ( I must stop this alliteration with your name Az!) it is a relief feeling.

It's even better when you say 'as az has' said.


az

Thanks for all those replies, everyone! My mind is at rest now...

Mine's clicking over...

B

Sounds like you have problems...