Hypermobility - Causes

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 or other connective tissue defect (found in Ehlers-Danlos syndrome, Marfan syndrome) resulting in weakened ligaments/ligamentous laxity, muscles and tendons. This same defect 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)

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

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 should 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 one.

Most people have hypermobility with no other symptoms. In fact, approximately 5% of the healthy population have hypermobile joints. However, people with "joint 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 syndrome can also lead to chronic pain or even disability in severe cases. Instrumentalists with hypermobile fingers may have difficulties when fingers collapse into the finger locking position.

Hypermobility may also be symptomatic of a serious medical condition, such as Stickler Syndrome, Ehlers-Danlos syndrome, Marfan syndrome, rheumatoid arthritis, osteogenesis imperfecta, lupus, polio, Down 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 pregnancy-related pelvic girdle pain can be debilitating due to these two converging factors, and prohibits them from standing up or walking. Use of a bedpan and wheelchair may be necessary, or even permanent in some cases due to hip stretching.

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