The Effect of 6 Months of Local Vibration Training of the Thigh and Hip on Muscle Strength, Muscle Mass, Bone Density, Bone Structure and Functionality in Institutionalized Elderly.

As the world population ages, osteoporosis (skeletal fragility) and sarcopenia (decline in muscle mass and muscle strength) are becoming increasingly important public health concerns. Both osteoporosis and sarcopenia contribute to an increased fall risk and an increased number of hip and vertebral fractures. Clearly, the clinical and economic consequences of osteoporosis and sarcopenia, and the resulting falls and fractures, call for major efforts to search for efficient and feasible interventions to prevent or reverse bone and muscle loss. The present project is intended to partly meet this need.

Whole Body Vibration (WBV) training might be an efficient training method. During WBV the subject stands on a platform that generates vertical sinusoidal vibrations. These mechanical stimuli are transmitted to the body where they stimulate the bone and reflexive muscle contractions will be generated. In previous studies performed by the same group, the investigators found that WBV training (frequency 30-40Hz, peak acceleration 3-10g) can be seen as an efficient alternative for strength training, both in the young sedentary as well as in the elderly population. Additionally, the investigators were able to show that 6 months vibration training in elderly females resulted in a net benefit of about 1.5% in bone mineral density of the hip compared with controls. Finally, the investigators have recently shown that long-term vibration training results in an increase of quadriceps muscle mass.

From the above it appears that vibration therapy could be a plausible candidate as an efficient combination therapy for elderly subjects at risk for osteoporosis and sarcopenia and, by implication, the therapy might help to reduce the number of falls and fractures. However, many questions regarding vibration as a therapy still need to be answered in order to optimize both the efficacy and safety of its application. The application methods of vibration therapy should be optimized to be applicable in a broader range of subjects as well as to deliver the stimuli more targeted to specific regions of interest. Whole body vibration in its present form (subjects standing on a vibrating platform) is inadequate for a large part of the elderly population (e.g., subjects with osteoarthritis at the knee, wheelchair bound subjects, bedridden subjects). Additionally, the transmission of the vibration stimulus from the feet to the hip during WBV is probably insufficient to provoke optimal adaptations at this level. Delivering the vibration stimuli locally (i.e. more targeted) at those regions at risk for fractures or in need for muscle strengthening might be an efficient alternative application method.

The main aim of this pilot research is to obtain data that should allow the investigators to optimize the efficacy and safety of the vibration excitation pattern as well as to optimize the application method. With the ageing of the world population and the predicted rise in fall and fracture rates, appropriate strategies to combat muscle and bone loss will have far reaching implications in containing future health care expenditure for the elderly and in reducing the need for institutionalized care.