Hypermobility (joints)

Hypermobility (joints)
Specialty	Rheumatology

Hypermobility (also called double-jointedness, extreme-flex, hypermobility syndrome or hyperlaxity) describes joints that stretch farther than is 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 other contortionist performances. It can affect a single joint or multiple joints throughout the body.

Causes

Hypermobility generally results from one or more of the following:

• Misaligned joints
• Abnormally-shaped ends of one or more bones at a joint
• A Type 1 collagen defect (found in Ehlers-Danlos Syndrome, Marfan syndrome) results in weakened ligaments, muscles & tendons. This same defective process also results in weakened bones which may result in osteoporosis and fractures
• Abnormal joint proprioception (an impaired ability to determine where in space parts of the body are, and how stretched a joint is)

The condition tends to run in families, suggesting that there may be 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 is not to be taken literally, as an individual with hypermobility in a joint does not actually have two separate joints where others would have just the one.

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  A hypermobile hand
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  A hypermobile hand
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  Hypermobile fingers

Some people have hypermobility with no other symptoms or medical conditions. However, people with hypermobility syndrome may experience 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 the excessive weakness in the ligaments that support the joints).

Hypermobility may also be symptomatic of a serious medical condition, such as Ehlers-Danlos syndrome, Marfan syndrome, rheumatoid arthritis, osteogenesis imperfecta, lupus, polio, downs syndrome, morquio syndrome, cleidocranial dysostosis or myotonia congenita.

In addition, hypermobility has been associated with chronic fatigue syndrome and fibromyalgia. During pregnancy certain hormones alter the physiology of ligaments making them able to stretch to accommodate the birthing process. For some women with hypermobility pregnacy related pelvic girdle pain can be debilitating.

Symptoms of hypermobility include a dull but intense pain around the knee and ankle joints and also on the soles of the feet. The condition affecting these parts can be alleviated by using insoles in the footwear which have been specially made for the individual after assessment by an orthopaedic surgeon.

Hypermobility syndrome

Hypermobility syndrome is generally considered to comprise hypermobility together with other symptoms, such as myalgia and arthralgia. It is relatively common among children and affects more females than males.

Causes

Current thinking suggests that there are four factors: These four factors affect different people to varying degrees and each is explained in detail in the following sections.

• The shape of the ends of the bones: Some joints normally have a large range of movement, like the shoulder and hip. Both these joints look like a ball in a socket. If you inherit a shallow rather than a deep socket, you will have a relatively large range of movement, but only at these particular joints. If your hip socket is particularly shallow, then your hip may dislocate easily.
• Weak or stretched ligaments caused by protein or hormone problems: ligaments are made up of several types of protein fibre. These proteins include elastin, which gives elasticity, which may be altered in some people. Also, the female sex hormones alter the collagen proteins. Women are generally more supple just before a period, and even more so in the latter stages of pregnancy, because of the effect of a hormone called relaxin. This hormone allows the pelvis to expand so the head of the baby can pass through. Different races have differences in their joint mobility, which may reflect differences in the structure of the collagen proteins. People from the Indian sub-continent, for example, often have much more supple hands than Europeans.
• The tone of your muscles: The tone (or stiffness) of your muscles is controlled by your nervous system, and influences the range of movement in the joints. Some people use special techniques to change their muscle tone and increase their flexibility. Yoga, for example, can help to relax the muscles and make the joints more supple. Gymnasts and athletes can sometimes acquire hypermobility in at least some of their joints through the exercises they do in training.
• Your sense of joint movement (proprioception): if you find it difficult to detect the exact position of your joints with your eyes closed, then you may develop hypermobile joints because you are likely to over-stretch a joint before you notice you are doing so.

Symptoms

People with hypermobility syndrome may develop other conditions caused by their unstable joints. These conditions include:

• Joint instability causing frequent sprains, tendinitis, or bursitis when doing activities that would not affect the normal individual.
• Early-onset osteoarthritis
• Subluxations or dislocations, especially in the shoulder
• Knee pain
• Back pain, prolapsed discs or spondylolisthesis
• Joints that make clicking noises
• Susceptibility to whiplash
• Temperomandibular Joint Syndrome also known as TMJ
• Increased nerve compression disorders (i.e. carpal tunnel syndrome)
• The ability of Finger Locking

Diagnosis

Joint hypermobility syndrome needs to be distinguished from other disorders that share many common features, such as Marfan syndrome, EDS, and osteogenesis imperfecta. Generalized hypermobility is a common feature in all these hereditary connective tissue disorders and many features overlap, but often distinguishing features are present that enable differentiating these disorders. Distinguishing features include:

• exceptionally soft or stretchy skin
• high and narrow palate
• dental crowding
• Varicose Veins
• Bruising easily
• Mitral valve prolapse
• tricuspid regurgitation
• Uterine prolapse
• Separated Pubic Symphysis
• Postural orthostatic tachycardia syndrome
• neurally mediated hypotension
• Hashimoto's thyroiditis
• More generalized joint hypermobility, usually with a Beighton score above 7

Treatments

Physical therapy

It is important that the individual with hypermobility remain extremely fit - even more so than the average individual - to prevent recurrent injuries. Regular exercise and physical therapy or hydrotherapy can reduce symptoms of hypermobility, because strong muscles help to stabilise joints. These treatments can also help by stretching tight, overused muscles and ensuring the person uses joints within the ideal ranges of motion, avoiding hyperextension or hyperflexion. Low-impact exercise such as Pilates or Tai Chi is usually recommended for hypermobile people as it is less likely to cause injury than high-impact exercise or contact sports.

Moist hot packs can relieve the pain of aching joints and muscles. For some patients, ice packs also help to relieve pain.

Medication

Medications frequently used to reduce pain and inflammation caused by hypermobility include analgesics, anti-inflammatory drugs, and tricyclic antidepressants. Some people with hypermobility may benefit from other medications such as steroid injections or gabapentin, a drug originally used for treating epilepsy.

Lifestyle modification

For many people with hypermobility, lifestyle changes decrease the severity of symptoms. For example:

• If writing is painful, people may be able to reduce the pain by typing.
• If typing is painful, they may try voice control software for their computer.
• Posture should be closely monitored. Weakened ligaments and muscles contribute to poor posture, which may result in numerous other medical conditions.

Other treatments

• Bracing to support weak joints may be helpful when joints are injured or painful, but caution must be used not to weaken the joints further.
• Those who are overweight should lose weight. The extra weight puts additional stress on the already weakened ligaments, making them more susceptible to injury.

External links

• Oxford Journals Rheumatology, Living with Hypermobility Syndrome
• Joint hypermobility syndrome Review from Journal of Indian Rheumatology Association presently Indian Journal of Rheumatology
• The Disability Handbook on Arthritis
• Association Between Joint Hypermobility Syndrome and Panic Disorder