By James Bassil – Paediatric Physiotherapist
Hypermobility describes a child that has several joints that are more flexible than usual. This happens when the connective tissue which makes up the joint structure (capsule and ligaments) is more compliant (more easily stretched) than usual. Usually in children this is a benign condition and is called Benign Hypermobility Joint Syndrome (BHJS)
Hypermobility syndrome facts
- The joint hypermobility syndrome is a condition that features joints that easily move beyond the normal range expected for a particular joint
- Hypermobile joints tend to be inherited
- Symptoms of the joint hypermobility syndrome include pain in the knees, fingers, hips, and elbows
- Often joint hypermobility causes no symptoms and requires no treatment. Treatments are customised for each individual based on their particular manifestations
What is joint hypermobility syndrome?
The joint hypermobility syndrome is a condition that features joints that easily move beyond the normal range expected for a particular joint. The joint hypermobility syndrome is considered a benign condition. It is estimated that 10-15% of normal children have hypermobile joints or joints that can move beyond the normal range of motion. Hypermobile joints are sometimes referred to as ‘loose joints’, and those affected are referred to as being ‘double jointed’
What causes joint hypermobility syndrome?
Hypermobile joints tend to be inherited in specific genes passed on by parents to their children. It is felt that these certain genes predispose to the development of hypermobile joints. As a result, there is a tendency of the condition to run in families (familial). Genes that are responsible for the production of collagen, an important protein that helps to glue tissues together, are suspected of playing a role.
Joint hypermobility is also a feature of a rare, inherited, more significant medical condition called Ehlers-Danlos syndrome, which is characterised by weakness of the connective tissues of the body. Joint hypermobility is commonly seen in people with Down Syndrome.
Recognising joint hypermobility
One of the measures used in assessing hypermobility is the Beighton Scale.
A child over 6 and under 12 who scores a 7/9 is considered to be hypermobile.
Joints are held together by a joint capsule and ligaments which are made up of connective tissue. Connective tissue is a stiff material that has a little give and as the joint moves the capsule and ligaments stretch a little but, but still hold the joint surfaces together quite firmly and limit the amount of movement at the joint.
One of the common indicators of BHJS observed by parents are hypermobile knees. When a child with hypermobile knees stand, the knees bend backwards in such a way the knees lock into position and the quadriceps muscles do not have to work to keep the joint steady.
This is fine as long as the knees are locked – but as soon as the knees are bent a little, the quadriceps muscles have to work to keep the knee straight and if they are not strong enough the knee is less stable.
The hips, spine, ankles, shoulders, fingers, and elbows are also affected by increased laxity in the connective tissue.
In people with joint hypermobilty, the muscle sheaths are also more pliable which means that the muscles have less inherent stiffness and give more easily. The muscles have less muscle tone. The stiffness in muscles also means that the forces generated by the muscles as they contract are easily transferred to the bones to produce movement and stability. Because the muscles of children with hypermobility have more give, they are less efficient at transferring force from the muscle contraction to the bones. This means that the muscles have to work harder to produce movement and provide stability.
How BHJS affects a child’s posture and movement skills
The increased compliance (laxity) in the joints and the tendency to poor muscle strength and endurance affects a child’s movement skills in numerous ways:
- A characteristic posture in standing with knees bent backwards and a slightly protuberant abdomen
- Child may not like standing erect and always something or someone to lean on
- Slumped sitting posture or sitting propped up on one knee
- Poor endurance – tire very quickly, find school very tiring
- Lack of strength and endurance for many childhood activities, such as climbing on the jungle gym, riding scooters, playing ball games, keeping up in the playground
- May have pain in the legs when walking or at night – this is usually due to the tightness in the muscles
- If the hypermobility is associated with a very cautious nature, the child will also avoid activities
Disclaimer: This is intended to support, not replace, discussion with your doctor or healthcare professionals. This information sheet has been compiled from various publications and considerable effort has been made to ensure the information is accurate, up to date and easily understood. Advanz Health accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in this information sheet.