Joint hypermobility: What causes 'loose joints'?

"Loose joints" is a lay term that may be used to describe hypermobile joints. Joint hypermobility — the ability of a joint to move beyond its normal range of motion — is common in children and decreases with age.

Having a few hypermobile joints isn't unusual. In most people, joint hypermobility causes no problems and requires no treatment.

But in some people, hypermobility causes joint pain and results in a higher incidence of dislocations, sprains and secondary osteoarthritis. Doctors refer to this as benign hypermobility syndrome. In benign hypermobility syndrome, the ligaments that provide joint stability are loose and weak. This increases the risk of ligament injury or strain and can cause pain.

If you have joint pain and other symptoms of hypermobility, your doctor may check for specific signs, which include the ability to:

• Bend your little fingers backward to a 90-degree angle
• Bend your thumbs to your forearms
• Hyperextend your elbows 10 degrees beyond neutral
• Hyperextend your knees 10 degrees beyond vertical
• Bend forward with your knees straight and place your hands flat on the floor

Results of this assessment are known as Beighton scores. The highest possible Beighton score is 9 — one point for each hypermobile joint. A Beighton score of 4 or higher, along with pain in at least four joints for more than three months, indicates benign hypermobility syndrome.

Treatment of benign hypermobility syndrome includes:

• Physical therapy to strengthen joints and learn how to prevent hyperextension
• Activity modification to relieve pain
• Pain relievers (analgesics)

Occasionally, joint hypermobility is a sign of a rare, serious disorder, such as Ehlers-Danlos syndrome or Marfan syndrome. For this reason, joint hypermobility accompanied by joint pain should be evaluated by a doctor to determine the cause.