Deborah Eastwood and Rosemary Keer explain how to identify and support children with loose joints.
A hypermobile child is one whose joints display an excessive range of movement in all directions compared to their peers when age, gender and ethnic background are taken into consideration. Joint laxity is greatest at birth and progressively decreases through childhood, adolescence and adulthood. True hypermobility is, therefore, common in children, with reports quoting prevalences varying from 7% to 43%, depending on the population studied and the assessment measures used (1,2).
Joint hypermobility is either congenital, resulting from an inherent laxity in the connective or collagenous tissues that go to make up the structure of the body, or acquired through hard work and training, as with dancers and gymnasts. There are many different types of collagen within the body: type I collagen is most common, being abundant in tissues such as tendons, skin, ligaments and joint capsules. Type III is found to a lesser extent in these tissues but is generally more elastic and found in more extensible connective tissue such as skin, lungs and the vascular system. In children, the increased flexibility is thought to be linked to a change in the ratio between type III and type I collagen (3).
Hypermobility is easy to recognise if you look for it and equally easy to miss if you do not (4). There is no definitive way to test if a child is hypermobile, but the Beighton score (5) (see Table 1 below) has proved easy and popular to use, although it has not been validated in children. It has also been criticised as it only tests a few joints and frequently other areas such as the neck, shoulder, hip and foot are important as signs of hypermobility.
|Joint action||Range of movement||Score|
|Elbow extension (fig 1)||>= 10 degrees||1||1|
|Knee extension (fig 2)||>= 10 degrees||1||1|
|Thumb apposition (fig 3)||To meet anterior aspect of forearm||1||1|
|Fifth finger extension (metacarpo-phalangeal) (fig 4)||>= 90 degrees||1||1|
|Forward flexion (fig 5)||Palms flat on floor with knees straight||
There is no universally accepted cutoff point, but a score of 4 or more out of 9 is generally accepted as indicative of hypermobility.
Hypermobility affects girls more than boys and for the most part does not cause any problems. It can even be considered to be advantageous in certain activities such as ballet and gymnastics, where increased flexibility is required to excel.
However, hypermobile tissue is generally thought to be less resilient and more susceptible to injury and can therefore be a cause of pain in childhood. Hypermobility Syndrome is a specific diagnosis and is always worth considering in children who complain of pain for no apparent reason. While it should never become a diagnostic ‘dumping ground’ for all childhood aches and pains, it is frequently not recognised, which can have repercussions for the child, as they are dismissed as making it up or ‘just’ having growing pains or emotional problems.
The most common symptoms are joint and muscle aches in the back or lower legs after unaccustomed or vigorous physical activity, or after prolonged inactivity. Symptoms may be aggravated or even precipitated during periods of rapid growth (growth spurts) or at menarche. Children may also report a tendency to ‘clicky’ joints and feelings of vulnerability or ‘instability’ as if their joints are ‘going out of place’. They may also suffer from subluxations and dislocations (commonly the shoulder and patella) and a higher frequency of soft tissue sprains and strains occurring with less provocation.
However, their increased flexibility may offer some protection against serious ligament damage (meaning rupture) or bone injury. Our experience has been that there have been times in clinical practice where a fracture would have been suspected given the trauma, but in a hypermobile child a severe soft-tissue strain rather than a fracture has been the result.
There is some evidence in the literature for this trend as Stanitski (6) found that hypermobile individuals were 2.5 times less likely to suffer articular cartilage surface damage with patellar dislocation than nonhypermobiles. The soft tissue injury in patients with hypermobility heals well but there are anecdotal suggestions that it may take slightly longer to heal.
Unexplained persistent pain in children and adolescents needs investigation but usually by means of a careful history and full examination rather than with invasive tests. The hypermobile child rarely has any positive laboratory findings or radiological abnormalities and so no evidence of a systemic rheumatological/inflammatory disorder. Joint hypermobility in the presence of musculoskeletal symptoms but in the absence of any other cause suggests a diagnosis of Joint Hypermobility Syndrome.
Parents often notice that their hyper- mobile child is clumsy and uncoordinated and this may be associated with generally lower muscle tone. Hypermobile children may also have been slow to walk and crawl, and may even have missed out crawling completely, because of their lack of stability around the shoulder girdle.
Hypermobile individuals ‘can’t keep still’. They dislike maintaining static postures for prolonged periods of time and often fidget to try to become more comfortable. In an attempt to gain more stability and a feeling of security, hypermobiles have a tendency to rest at the end of their joint range, tensioning their soft tissues rather than using muscle activity. Common examples include ‘hanging on the hip’ (fig 6), hyperextending the knees in standing and ‘W’ sitting (fig 7). These postures have the potential to cause ligament creep with gradual elongation leading to strain, microtrauma and pain in the long term. It is important therefore to encourage a more neutral joint position, evenly balanced weight bearing, better body awareness and active muscle control during static postures.
Lower limb pain can affect the knees, ankles or feet, often after a bout of physical activity or towards the end of the day. Children may also complain of stiffness, but unlike with rheumatological disorders there is usually no sign of inflammation or swelling in a presentation associated with hypermobility.
There is also thought to be an association with ‘growing pains’ or ‘benign paroxysmal nocturnal leg pain’ as many children who complain of this are found to be generally hypermobile and many hypermobiles seen later in life report having suffered from growing pains. Anterior knee pain or patello-femoral problems and hyperextending knees are very common in hypermobile individuals, as are flat feet or the over- pro-nated foot. All can contribute to poor alignment and biomechanics throughout the limb, which can adversely affect joints above or below.
Back pain tends mainly to affect adolescents and is often associated with poor posture, although the incidence of lumbar disc prolapse, pars interarticularis defects and spondylolisthesis are all more common in hypermobile individuals. Sitting posture is particularly important as children can spend a lot of time in front of a computer, at a desk in school or playing electronic games in slouched and unsupported positions, which exacerbate the pain and strain on ligaments. Carrying large numbers of schoolbooks in a bag slung over one shoulder can also add to the problem.
Conservative management is the treatment of choice for back pain associated with hypermobility – even where there is a definitive orthopaedic pathology such as a pars defect. Surgery should be limited to cases with significant physical signs (specifically neurological signs).
Occasionally, limb or back pain can become chronic and there is some evidence to suggest a link between hypermobility and fibromyalgia (7). Hypermobile children frequently complain of fatigue and tiredness, often getting into an overactivity-underactivity cycle which can begin to affect their normal functioning.
For the child or adolescent who is suffering symptoms attributable to their joint hypermobility, assessment and treatment by a physiotherapist can be very helpful. The aim is to reassure the child and their parents about the diagnosis, help them to understand the condition and work with them to develop a plan which enables them to manage the problem now and for the future. This should include a detailed assessment to identify specific problem areas before developing an individual management plan. This plan will usually include:
Postural re-education: This can be difficult for hypermobile individuals as there is evidence to show that their proprioceptive acuity is decreased (8) and hence they have a poorer awareness of their body in space. Working on sitting and standing posture with the aid of biofeedback in the form of mirrors, photographs or video can be helpful.
Proprioception and balance training: This can be made enjoyable for children with the careful use of balance boards, Swiss balls and exercises involving standing on one leg with a ‘soft’ knee, walking on uneven ground and closed chain exercises such as deep knee bends, squats, bridging and exercises on hands and knees. Closed chain exercises are thought to put less strain on joint ligaments and also facilitate joint proprioceptors and cocontraction of muscles around the joint, enhancing stability.
Trunk stability: This is particularly important for children suffering from back pain, but is also a vital ingredient for improving stability in peripheral joints. Older children can be taught to recruit their deep abdominal (transversus abdominis) muscles with their pelvic floor, while maintaining a good breathing pattern and a neutral spinal posture. This is achieved initially in static positions and gradually progressed to more challenging positions and incorporated into everyday life activities. Younger children can be encouraged to use their trunk muscles by sitting on a ‘sit-fit’ (an air-filled cushion), or on a gym ball while doing closed chain exercises, with one or both feet on the ground – stability is challenged by single-leg balance and / or arm and trunk movements.
Muscle re-education and strength training: Introduce exercises which target individual muscles, such as the gluteal and quadriceps muscles for lower limb problems. These can be progressed to include resistance for improved strength and more repetitions for improved endurance.
Fitness: Children with pain will often become sedentary and unfit. It is important to introduce aerobic exercise to improve general fitness, stamina and confidence so that the child can begin to participate in physical education and sports. Initially recommend low- impact activity, such as cycling, walking or swimming.
Advice and problem-solving: There may be individual problems with which a therapist can help with the use of aids and supports. In general the use of supports is discouraged, but there are occasions when one can be helpful to allow a child to participate in an activity that pain may otherwise make impossible. This might be the use of a splint for the wrist or thumb to allow writing, or the use of a knee support during physical activity. It should be stressed that the support is only temporary and is to be used in combination with exercises designed to strengthen the area, with the aim of being able to do without the support over time.
All children should be encouraged to take regular exercise, play sport or dance, but it is even more important for the hypermobile child. Physical activity helps to improve cardiovascular fitness, muscle development, strength and control, coordination and stability; and it creates a feeling of confidence and wellbeing. There are no particular recommendations on preferred activities, but the following considerations may be helpful:
If a hypermobile child experiences pain on performing some physical activity or sport, it is helpful to identify the cause of the pain and put in place specific corrective measures to allow them to continue. These can include providing orthotics for the child with flat feet, or developing a specific exercise or training programme to address the particular needs of the child and/or the activity. It is important to try to prevent the child being excluded from certain activities or sports, and to this end it is very helpful for the physical therapist to liaise with the child’s teachers, sports coach or trainer.
Therapists, coaches and parents should not ignore pain that continues during exercise. Children and their families can be extremely motivated to succeed, but even hypermobiles who seem inherently well-suited to gymnastics, for example, may not be able to develop the necessary motor skills to allow them to excel at the higher/highest level. In such circumstances, persevering with the exercise may do harm and the child, their family and their trainer must understand this.
Those who are working hard to acquire increased joint laxity by training must also be aware that the impossible is not always achievable and perhaps not all children can do the ‘splits’, even if they work and train really hard. These children, like those with true hypermobility, can be pushed too hard and too fast and harm can ensue.
Specific injuries need to be treated appropriately and essentially in the same manner as a similar injury in a non-hypermobile child. Hypermobile tissue heals well. As with all children, once an injury has recovered a graduated return to the child’s pre-injury activity level should be advised, remembering that during the period of injury general fitness levels may have dropped off. It can be helpful to introduce some cross training once the patient is ready to return to sport.
Deborah Eastwood MB FRCS is a consultant paediatric orthopaedic surgeon, based at the Hospital for Sick Children, Gt Ormond St, London and the Royal National Orthopaedic Hospital. Her special interest is in working with disabled children in sports and non-sporting contexts
Rosemary Keer MSc MCSP MACP is a chartered physiotherapist with a clinical and research interest in the management of the hypermobile patient. She is editor (with Rodney Grahame) of Hypermobility Syndrome – Recognition and Management for Physiotherapists, pub: Butterworth-Heinemann 2003