Neuromuscular impairments in children diagnosed with hypermobility syndrome: a preliminary study

Impaired joint proprioception has been found in association with hypermobility syndrome (HMS) (Mallik et al. 1994; Hall et al. 1995). However, it is uncertain if other neuromuscular indices in children with HMS are impaired. Therefore, this study investigated a range of neuromuscular impairments in healthy children and those diagnosed with HMS. Seventeen healthy girls (mean age 11.3±S.D. 2.5 yr) and 13 girls diagnosed with HMS (mean age 11.8±S.D. 1.3 yr) participated in this investigation. The study was approved by the Education Department, City of Edinburgh Council, and the QMUC and NHS Lothian Local Research Ethics Committees. Informed written consent was obtained from the participants and their parents. Knee joint kinaesthesia (KI) was assessed at 60 degrees of knee flexion and joint position sense (JPS) was examined at both 25 and 10 degrees of knee flexion using a motorised proprioception measuring device. Absolute angular error (AAE) was calculated as the difference between the target and perceived angle for JPS tests. Quadriceps and hamstrings muscle torque was measured in high sitting with the test knee in 90 degrees using a digital myometer. Muscle torque was normalised to body weight. Mann-Whitney U tests were used to compare the variables between the two groups. The knee joint proprioception outcome measures were significantly different in children with HMS and they also showed weaker quadriceps muscles than the healthy controls. However, there was no hamstring muscle strength deficit between the two groups. Clinicians should be aware of these identified impairments in children with HMS, and a programme of proprioception and muscle strengthening exercises may be indicated