Joints that are more flexible than normal, or that have a greater range of motion than expected, are considered hypermobile. People with hypermobile joints are sometimes called “double jointed.” Children with hypermobility may experience joint or muscle pain, but they might not have a true, underlying inflammatory disease.
Those who have hypermobility syndrome (also sometimes called joint hypermobility syndrome or JHS) experience pain and inflammation in the joints due to their increased flexibility. In some patients, hypermobility syndrome can be associated with other hereditary (genetic) disorders of connective tissue (HDCT), such as Marfan syndrome, Ehlers-Danlos syndrome and osteogenesis imperfecta. Hypermobility syndrome can also be associated with postural orthostatic tachycardia syndrome (POTS).
Hypermobility tends to run in families, and girls are usually more symptomatic than boys. Not all children with hypermobility experience pain or inflammation, and it is unknown why some children develop pain while others do not. Typical complaints include:
Children with genetic connective tissue disorders may have other issues as well, including abnormally tall stature, vision problems, skin abnormalities, and cardiac (heart) problems.
Hypermobility is diagnosed based on physical exam. Doctors may use a scoring system called the Beighton Hypermobility Score to assess the level of joint hypermobility. Children with features suggestive of a genetic connective tissue disorder may be referred to a cardiologist for an echo cardiogram, an ophthalmologist for an eye exam, or a geneticist for further workup. Although lab work and imaging are not typically necessary to diagnose isolated hypermobility, these may be performed to rule out other conditions.
The most important principle of treating children with hypermobility is strengthening the muscle groups that help support the hypermobile joints. Physical and occupational therapy play a major role, as do activity modification and family education. Many children become less hypermobile as they grow, and symptoms may improve over time.