Scoliosis is a three-dimensional spinal deformity and AIS is the commonest with a high prevalence of 2-4 % in the general population. As many as 30% of AIS subjects also suffer from osteopenia which can persist and result in serious health problems later in life including vertebral collapse, fragility fractures, decreased quality of life and even mortality. In spite of this, a safe, effective and evidence-based treatment protocol for AIS-related osteopenia is not available. It remains uncertain how effective dietary advices, physical activity, Calcium and Vitamin D supplements are in this regard. On the other hand, low-magnitude high-frequency vibration therapy was shown to be effective in increasing bone mass both in animal models and in clinical trials involving elderly subjects. AIS-related osteopenia may have a different clinical behaviour. In addition, the in-vivo effect on bone quality has never been studied. We plan to carry out a scientific clinical study on the effect of vibration therapy on skeletally mature female AIS subjects with osteopenia. They are randomly allocated to either the treatment or the control group. BMD, bone micro-architectures are assessed to delineate whether vibration therapy has any therapeutic effect on improving low bone mass in osteopenic AIS subjects.