What Does it Mean to be “double-jointed” ?
Should you discover that you have the ability to bend the upper half of your thumb until it makes a right-angle you might feel rather chuffed with yourself as you can then describe yourself as “double jointed” – surely that means you have two joints where most people have one ?
NO, unfortunately not!
However I guess that the correct medical term – hypermobility – is no less exciting, though it does simply mean that one possesses highly elastic ligaments which allows the joints to reach angles most people’s can’t.
Someone with hypermobility can perform all sorts of amazing feats, such as bending the thumb right back until it touches the forearm or moving their knees left and right as well as forwards.
Many children have some hypermobile joints, because their ligaments have yet to grow strong enough to restrict movement (which explains why 7 year olds can sit in the lotus position with impunity) but everyone can attain some level of hypermobility through exercise, especially yoga. It’s also been noted that it is a trait that tends to run in families, especially in those with tall fathers; scientists suspect there is a strong genetic link.
Other factors that can contribute to having hypermobile joints include :
|The bones in your joints sockets may by unusually shallow so there can be a greater range of motion but also may be a greater risk of dislocation.
|Poor muscle tone, which may be due to nervous system impairment, can result in abnormally relaxes muscles and more movement in your joints.
|Abnormal proprioception, sensing of the position of the joint, can lead to overextending it without feeling you are doing so. (see our article entitled Extra Senses – Beyond the ‘traditional five’)
|People with Down syndrome, Marfan syndrome, osteogenesis imperfect, and Ehlers-Danlos syndrome often have joint hypermobility.
|Training and exercise, such as yoga and athletic training, can increase your range of motion and joint mobility.
|Finally, as already mentioned, you may have abnormal collagen or elastin fibers due to an inherited trait. As these fibers make up the ligaments that hold joints together, your joints will be looser.
However there is a cost to hypermobility : those with the syndrome often suffer more than their share of injuries, aches and pains and run a higher risk of developing osteoarthritis.