Joint hypermobility

Hypermobility
Synonyms	hyperlaxity, benign joints hypermobility syndrome (BJHS), hypermobility syndrome (HMS)
Hypermobile fingers and thumb
Classification and external resources
Specialty	Rheumatology
ICD-10	M35.7
ICD-9-CM	728.5
OMIM	147900
DiseasesDB	31101
MedlinePlus	003295
MeSH	D007593
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Hypermobility, also known as double-jointedness, describes joints that stretch further than normal. For example, some hypermobile people can bend their thumbs backwards to their wrists, bend their knee joints backwards, put their leg behind the head or perform other contortionist "tricks". It can affect one or more joints throughout the body.

Hypermobile joints are common and occur in about 10 to 25% of the population. It is usually not associated with any symptoms but a minority of people develop other conditions caused by their unstable joints; in such cases, it is known as joints hypermobility syndrome (JHS).

Joint hypermobility syndrome is sometimes interchangeably called Ehlers–Danlos syndrome hypermobile type. As no genetic test can identify or separate either conditions and because of the similarity of the diagnosis criteria and recommended treatments, many experts recommend they should be recognized as the same condition until further research is carried out.

People with Joint Hypermobility Syndrome may develop other conditions caused by their unstable joints. These conditions include:

Those with hypermobile joints are more likely to have fibromyalgia, mitral valve prolapse, and anxiety disorders such as panic disorder.

Hypermobility generally results from one or more of the following:

These abnormalities cause abnormal joint stress, meaning that the joints can wear out, leading to osteoarthritis.

The condition tends to run in families, suggesting a genetic basis for at least some forms of hypermobility. The term double jointed is often used to describe hypermobility; however, the name is a misnomer and should not be taken literally, as hypermobile joints are not doubled/extra in any sense.

Most people have hypermobility with no other symptoms. Approximately 5% of the healthy population have one or more hypermobile joints. However, people with "joint hypermobility syndrome" are subject to many difficulties. For example, their joints may be easily injured, be more prone to complete dislocation due to the weakly stabilized joint and they may develop problems from muscle fatigue (as muscles must work harder to compensate for weakness in the ligaments that support the joints). Hypermobility syndrome can lead to chronic pain or even disability in severe cases. Musical instrumentalists with hypermobile fingers may have difficulties when fingers collapse into the finger locking position. Or, conversely, they may display superior abilities due to their increased range of motion for fingering, such as in playing a violin or cello.

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Wikipedia