Hardy Blogs
Matt Hardy

Joint noises… What are they?

Welcome to (or back to) my blog. Today I want to talk about something that happens to us all, whether young, old or somewhere in between: noisy joints.

What are joint noises?

Joint noises are the physics of our biology. All a noise in a joint is, is something is happening. Not normally anything problematic, just something happening. Have you ever seen a machine move without making a noise? The answer is no and we’re no different.

Before we move any further, it’s important for us to talk about the golden rule. If it doesn’t hurt don’t worry about it!

What can cause joints to be noisy?

The first and most common joint noise that we get is a discharge of gas from the synovial fluid in the joint. The job of this fluid is like oil in an engine, its a lubricant but it also helps to nourish and sweep out waste products/debris from the joint. The gas is able to escape the fluid when pressure in the joint drops.

Let’s think of a can of coke. When you open the can you increase the gas volume of the can by exposing it to the atmosphere. This means that the gas that’s dissolved into the liquid and held in there by pressure when the can is closed now has nothing holding it in. That’s why you hear the pop when you open the can. Now obviously when your knee cracks you’re not (hopefully anyway) exposing the joint to the atmosphere. But when you move your knee to a position it hasn’t been for a while the capsule that surrounds the joint and keeps the gas in expands, increases it volume and allows gas to escape from the liquid causing the cracking noise. You can even see a gas bubble form under high powered ultrasound scanning. Thats why if you crack your knuckles, you can’t crack them again straight away**. This is the exact noise that you get if you have your spine manipulated. Thats not bones ‘going back in place’, they were never out of place in the first place but we’ll discuss that more in a future blog.

**Quick one, knuckle cracking doesn’t cause arthritis. Its been researched over a long time period and there’s no increase in arthritis in knuckle crackers over non-knuckle crackers**

The second most common cause of noise is fluid passing through a joint. Again if we think about the physics of the joint, your got fluid under pressure being pushed around as your bones move. This can cause fluid to be pushed through small or larger spaces. This in turn can cause release of gas or you can just physically hear the fluid moving in the joint. The most common joint to hear the fluid moving is behind the knee cap. If you have noise in your knees that sounds like crackles and repeats every time you go up the stairs, its most likely from fluid moving in the joint.

There are a few structural things that can cause noises. The first being tendons. If a tendon flicks either in and out of a groove that it sits in or over a bone it runs along, this can cause a noise. This for some can be a result of how your bony anatomy is set up and for some this can be a sign of instability in the related joint. This is common in the hips of young women as they’re growing.

The other structure that can cause noises is bones. Bones make a quick deep clunk noise and sound very different to the high pitched snaps and cracks or gas release. These again are not always linked to a problem. A common area for this to happen is around the collar bones and breast bone. The joint around those bones are very mobile and sometimes if they haven’t moved for a while they can clunk as they get moving. Again nothing to worry about.

The last thing I want to talk about is arthritis. The development of osteoarthritis is a normal part of the ageing process that happens to us all at some level. Think about it as ageing on the inside. Unfortunately wrinkles and grey hairs are inevitable for most of us, as is some degree of arthritis. This type of arthritis is essentially a roughening of the surface of the joint. Now if we think about this in the joint noise sense, that can be a cause of noise by how it interacts with the synovial fluid we spoke about earlier. As the fluid passes over a smooth non arthritic joint, the fluid slows down, but in a very even manor. Pass that over a rougher surface and the fluid with rotate or turbinate. This can cause a release again of the gas like we spoke about earlier and can also cause noise itself in the same way we spoke about pressure in the joint above. This again is something that isn’t anything to worry about and as long as the joint works as normal.

When should we worry about bone noises? Simply put, If it hurts. If you have a joint that is painful, noisy, swollen, red, hot and not moving as it would normally would get it checked out you probably have an injury that needs treating.

I hope that quick recap of joint noises helps and you enjoyed reading about them.

If you do want to book in for a 1-1 session to assess your breathing or you have an injury, ache or pain you can do so by using this link, I’d love to help.

Until next time

Matt