We have all been told stories at some point during our lives like, “don’t pull that silly face, if the wind changes you’ll get stuck like that”. But how many of us have been told by friends or family that cracking your knuckles is bad for your hands and can cause arthritis?

Image by: stakerchiro

Image by: stakerchiro

This commonplace wives tale is quite an inaccurate miss-conception of what “cracking a joint” really causes or achieves within the human body. Osteopaths and Chiropractors alike utilise the skill of joint manipulation for a variety of reasons within their treatment plans which can result in a patient’s body feeling more mobile, having a larger and less restricted range of movement and in some instances it can completely alleviate a patients pain all together.

What causes the popping noise heard when a joint is ‘cracked’?

Although the research around the area is a bit woolly, recent evidence suggests that the popping noise could be caused by a build-up of carbon dioxide within a joint capsule collapsing. In engineering terms this is known as a ‘cavitation’ which refers to the formation of a vapour cavity within a liquid. The changing in pressures within the liquid of a dynamic environment causes the formation of cavities or ‘voids’ which when subjected to areas of high pressure can collapse causing a popping sound. When related to a joint in a human body, a joint capsule surrounds the area at which the two bones meet. This is  filled with synovial joint fluid which helps to lubricate the area. When the joint moves in everyday activities, the pressure changes can cause similar cavities to that in the engineering model but this gas consists of carbon dioxide. If someone was to apply pressure to this joint in a certain way, it can cause this bubble of gas to pop resulting in a clicking or popping sound. Think of popping some bubble wrap!

Joint

What are the benefits of popping a joint?

One of the biggest benefits from having a joint manipulated is to increase its range of movement. In an otherwise stiff or immobile area of the body such as the spine, this technique can be applied to greatly improve the amount of movement that the joint can move through. Indirectly, a stiff neck can occur from a lack of movement in the lower spine meaning the neck has to move more and gets tired and achy. If the area of the lower spine can be identified and freed up via a manipulation technique it can take the emphasis off of the neck which can help to reduce pain and improve all round function. Another benefit of joint manipulation is to free up pain sensitive structures within the joints that may have become stuck in between the joining parts of two bones. When the joint is manipulated it essentially helps to ‘gap’ the area releasing and trapped structures that may be causing a patients pain symptoms. This opening of the joint also results in an increased amount of fluid allowed in to the area so more metabolic waste can be transported out of the area and also more bodily fluids carrying essential nutrition can be more readily absorbed giving the area the best chance of healing quickly.

In 2009 a medical doctor named Donald Unger won the lg Nobel Prize in medicine, which is a parody version of the annual Nobel Prize, by confirming there is no harm in such an intervention. He did this by cracking the knuckles on his left hand every day for 60 years but never his right! Can you imagine only cracking one side of your knuckles and never the other for 60 years, what a commitment! After the 60 year period both hands were tested and imaged finding NO arthritis or other ailments in either of his hands!

So in conclusion, there is NO quantifiable or substantiated evidence to suggest that joint ‘cracking’ causes arthritis in the hands or fingers or in the rest of the human body for that matter! There have been no studies to date that have been able to conclude that cracking your knuckles will give you arthritis. However, there is evidence that suggests joint manipulation used by Osteopaths and Chiropractors have some very positive benefits to the human body. Although these types of techniques aren’t appropriate for everyone, it’s nice to know that this old wives tale about such an intervention as this does not in fact cause arthritis but actually has much more positive healing implications to the human body.

 Well that’s one wives tale down, I just hope it’s not windy outside………….

Written by Wayne Beck, Osteopath

References

Protopapas, M. Cymet, T. Protapapas, M. (2002). “Joint cracking and popping: understanding noises that accompany articular release”J Am Osteopath Assoc 102 (5): 283–7

Improbable Research (2015). Winners of the lg Nobel Prize. http://www.improbable.com/ig/winners/#ig2009 online [Access date 02/11/2015]

Unsworth, A. Dowson, D. Wright, V. (1971). ‘Cracking joints’. “A bioengineering study of cavitation in the metacarpophalangeal joint”. Ann Rheum Dis 30 (4): 348–58

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