I have seen an increase recently in some misconceptions around hypermobile joints across Twitter and Instagram, I want to address this for the benefit of professionals and patients who may come across this blog. There is a concern that a misconception around what is happening at a hypermobile joint could lead to worry or fear of a person about their body.
As usual feedback is greatly appreciated and any further reading for me please send it my way!
PLEASE REMEMBER – THIS BLOG IS NOT A REPLACEMENT FOR CLINICAL REASONING, IF YOU ARE UNSURE GET ADVICE
Disclaimer
In this blog I am NOT commenting on extra-articular features of hypermobility syndromes, Ehlers-Danlos variations or individual experiences. I am purely commenting on the biological nature / difference between hypermobility and instability as a means of discussion around the description of joints and resultant problems I have seen across social media.
Introduction
There is a push across social media to raise the profile of the cause of a variety of symptom presentations being related to Hypermobility Spectrum Disorder(s)/hEDS (hypermobile Ehlers-Danlos Syndrome)/and other variants. This is a positive step hopefully enabling appropriate investigation, diagnosis, education and management for individuals with these conditions.
With this widespread increase in awareness and visibility, I have noticed some misconceptions around what is happening at a joint level that keeps cropping up in threads. I hope this blog serves to clear up some of the muddy water.
With the hypermobility syndromes we must recognise that there is much more going on in the whole person than purely the mechanical properties of a joint. That mechanical property is just one factor.
Descriptions
Joint hypermobility – A joint that moves more than described “normal” ranges
Joint Instability – A joint that is lacking or has lost restrictions (muscular, boney, ligamentous etc.) to one or more movement planes
Some (but not all) hypermobile joints have instability.
Some (but not all) joints with instability have hypermobility (of normal ranges of motion for that joint).
Joint range of motion is hugely variable within the population. When we describe hypermobility of a joint this is measured against what we think is average and this is on a bell curve. Some people have a “normal” range for them which is significantly more than the population average (see finger pictures). This movement is “hypermobile” compared to population average but “normal” range of motion for me.
A crude comparison is that of height. The population mostly have a height between about 5ft4inch and 6ft but we all know people much taller or shorter than those top and bottom numbers. That doesn’t mean they had a problematic cause for their height its just an issue with mathematic averages.
A joint with instability in one person may increase in range and gain the ability to move the same as someone whose “normal” range was significantly more. This is not normal for that first person and should be thought of differently.
Imagine my girlfriend sustains a finger injury and her finger suddenly is able to move like mine. Her finger would be both hypermobile and have instability. An injury mechanism (tissue damage was required to get this new range of motion). Mine moves normally to that range and is not injured to get to that point. Her finger moving into this new range in the future is likely (but not guaranteed) to continue to be “injured” as this is still not the “normal” range.
The range of motion of my fingers is normal (for me) and function well and remain stable in these range of movements. I can do things in these ranges without concern because it is normal (for me) and as such is of equal robustness or resistant to injury as it is in normal (for everyone) ranges. See pushups video.
Joint properties and outcomes
This means when reading comments, threads or articles about hypermobile joints remember the following.
Hypermobile joints are not necessarily unstable joints (but sometimes they are)
Hypermobile joints are not necessarily more prone to injury (but sometimes they are)
Hypermobile joints are not guaranteed to become painful (but sometimes they do)
Moving Hypermobile joints in their normally available range is not injuring them under normal circumstances
Hypermobile joints are highly prevalent in the population, some of these are related to conditions/syndromes that cause other problems. Having a hypermobile joint or even multiple joints does NOT mean you have one of these conditions/syndromes however having them is characteristic of people with the conditions/syndromes. Some people with these conditions/syndromes do not have hypermobile joints! Its all very complicated.
If you have one of these conditions/syndromes your joints are not guaranteed to have instability nor are they guaranteed to be injured or painful in the future.
Some hypermobile joints are an advantage! Think of many Olympic gymnasts who are generally extremely flexible. In a more specific example, throwing athletes have extreme movements into shoulder external rotation allowing them to generate huge amounts of force.
End
I hope this has been useful, reassuring and interesting. It is important that we use the right terminology, understand what is normal and what is pathological and that this will vary wildly between individuals.
Get me any feedback you might have so that I can grow and improve.
See you next time!
