Collagen is an extremely important connective tissue protein in our bodies, making up significant amounts of our skin, tendons, discs and ligaments. Collagen gives structure to these organs, allowing them to heal normally, to have elasticity, to be strong and to hold together well under the stresses of functional life. It also gives our major blood vessels and other organs the strength they need to remain working correctly. People vary very greatly in the suppleness of their joints and skin and show the whole range from very stiff jointed to very mobile or "double jointed".

Ehlers-Danloss Syndrome (EDS) is an inheritable condition which affects the synthesis and viability of collagen as a structural protein. There are at least 10 forms of this condition but Ehlers-Danloss III (three) is also known as benign joint hypermobility syndrome, benign because there are no life-threatening symptoms as occur in some of the other types. These people have smooth, velvety and flexible skin and remarkably hypermobile joints, along with chronic joint or limb pains and recurrent joint dislocations, mostly of the shoulder and the patella. Slow or abnormal wound healing with large and relatively weak scars can also be a feature.

The typical signs and symptoms of joint hypermobility syndrome are a hyperextensible skin, hypermobile joints, tendency to dislocations, fragile tissues, poor wound healing and a tendency to bruise easily. Chronic joint and limb pain is also common and many sufferers live with constant and multiple pain complaints. Patients show many abnormal muscle balances and have difficulty stabilising their joints appropriately, causing incorrect muscle uses which can lead to pain problems. Functional limitation is common in this group, who cannot participate in contact or vigorous sports without significant joint injuries and pain.

Advice to patients is very important and education should be a priority to allow them to manage their condition over the long term. Avoidance of excessive or repeated heavy lifting and other movements which put stresses and strains on the hypermobile joints is important and patients should avoid end-range postures which strain the lax ligaments. Joint protection, as in arthritic joints, is essential and patients should avoid showing off by performing "party pieces" such as dislocating a joint voluntarily or other extreme tissue manoeuvres. Stretching the joints strongly may worsen the underlying problems, and any activity carrying high risk of skin damage should be avoided.

As it takes far less trauma to damage a hypermobile joint than a normal one the incidence of acute injuries is higher in these patients as they go about their daily activities. The joint injuries and general painful problems which occur are managed by physiotherapy intervention. The shoulder is a highly mobile but unstable joint in the best circumstances and in hypermobile patients it presents particular problems of stability. The socket is small and the shoulder girdle muscle control must keep the humeral head aligned against it, difficult if the pattern of muscle action is abnormal. Repeated subluxation or dislocation with consequent pain is common and difficult to treat.

Hypermobile patients complain commonly of neck, thoracic and lumbar pain, perhaps related to the difficulties keeping spinal stability and the correct muscle balances around the spine. Manipulation is likely to be unhelpful although mobilization techniques, general exercises, strengthening stability muscles and concentrating on core stability are all useful approaches. Gentle weight training can elevate muscle tone to allow the joints to be maintained in a mid range position during movement, avoiding too much play. Knee hyperextension is common and can lead to osteoarthritis, leading physiotherapists to work at the balancing muscles, the hamstrings, to counteract this. Patients often have a few areas of the body which need constant training for best muscle balance and control.

All postures and activities are a challenge to a patient with hypermobility as unsuitable stresses are very easy to apply, causing pain. The patterns of muscle activity are abnormal when the joints are under load, pushing them into end range positions where the ligaments and capsules suffer from strains. Physiotherapy retraining of poor muscle balance can be helpful but patients need to be constantly vigilant and work at their weaknesses persistently. The most important factor overall is patient education as the condition is a long term one and all physical activities challenge the joints.