The term hypermobility means ‘more movement’ and describes the over flexibility of the joints. Hypermobility syndrome (HMS) is an inherited condition in which the protein, collagen, which makes up the supporting tissues and gives the body its intrinsic toughness, is more flexible than usual. A person’s joints are lax because they have inherited looser and more brittle connective tissue, particularly their ligaments, tendons, joints and muscles. This makes the joints more mobile, sometimes unstable, thus more prone to injury. Some children may have more severe problems that may lead to subluxations (excessive movement of the joint) or dislocations. The degree of difference, and hence tendency towards painful symptoms, varies from individual to individual, even in the same family.
HMS is a composite term bringing together all the various difficulties that may arise in people with hypermobile or lax joints. It is probably more correct to refer to the hypermobility syndromes (in the plural) as a family of genetically based conditions which differ not only in the particular protein affected, but also in the degree of difference of formation. At one end of the spectrum are the diseases with potentially serious complications such as Marfan syndrome or Ehlers-Danlos syndrome vascular type (formally EDS IV) see entries. At the other end of the spectrum are what is now called, on good evidence, the benign joint hypermobility syndrome (BJHS) or Ehlers-Danlos hypermobile type (formerly EDS III). These may cause troublesome and persistent problems but do not affect the vital organs and thus do not pose a serious threat to life. Because joints do not look arthritic, the problem is often overlooked by health professionals.
Medical text written October 2001 by Professor Rodney Grahame. Last updated October 2006 by Professor Rodney Grahame, Emeritus Professor Rheumatology, University College London, London, UK and Dr Nathan Hasson, Paediatric Rheumatologist, Great Ormond Street Hospital, London, UK.
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Although some people with BJHS have little or no trouble, in others, pain can be a recurring or, in some, even a constant problem. This renders them prone to the effects of injury and over-use resulting in acute (short-term) pain on prolonged and unaccustomed exercise. More chronic day-in day-out pain is also seen and may require a variety of measures, which can vary from one person to another in order to control it.
About seven to ten per cent of the population of school-age children has been found to have loose joints and occasional pain in the joints and muscles, especially after exercise or at night. Most children with HMS complain of joint pains in the evening or sometime after exercise. These mostly occur in the knees, ankles or non specifically in the legs. Sometimes the joints may appear to be swollen. Swelling should be treated as with any injury: RICE (rest, ice, compression, and elevation). Young children generally do not like ice, but it can be used with older children. If the joint pain persists, a doctor should be consulted.
Children with HMS often wake up in the night complaining of pain in the legs. For the majority, symptoms will improve as they grow older as their supporting muscles and ligaments get tighter and this is why this used to be called ‘growing pains’ which we now feel does not exist.
Some may need to have physiotherapy, occupational therapy, podiatry and pain management through psychology to help strengthen specific muscles that stabilise joints and cope with their pain. It is important that children continue to exercise and do sport to build up their strength and muscles.
As in most of the heritable disorders of connective tissue, the pattern of inheritance for the BJHS is autosomal dominant. This means that 50 per cent of the offspring may carry the gene for the condition. In BJHS, this does not imply that they will inherit any particular set of symptoms, since many affected people have no ill effects at all. It used to be thought that hypermobility simply represented the upper end of the normal distribution of joint laxity. This view has been challenged as increasing evidence emerges to suggest that it is also a genetic connective tissue disorder, (albeit a relatively mild one) in its own right.
If a genetic form of hypermobility is known to affect members of a family, referral for genetic advice or counselling should be sought.
Hypermobility Syndrome Association (HMSA)
Helpline: 033 3011 6388
Email: via website
The Association is a Registered Charity in England and Wales No. 1011063 and Scotland No. SC037916. It provides information and support to those affected by one of the hypermobility syndromes. The Association has a network of support groups throughout the UK, an online forum, and a family programme.
Group details last updated June 2016.