3.3 Prevention of postmenopausal bone loss by a low magnitude, high frequency mechanical stimuli: A clinical trial assessing compliance, efficacy and safety

Journal: Journal of Bone Mineral Research. 2004; 19:343-351

Study Context: Rubin et al used 30 Hz of vibration with a tiny amplitude of 0.2 g. Subjects were given a machine for home use and they stood on it for 2 19 minute session per day for 12 months.

Results: In this study they found a decrease in bone loss of 1.5% in the spine and 2.17% at the femur. They also noted that bone mineral density gains were the greatest in women weighing less than 65 kg (143 lbs) who improved 3.35%

Comments: Researchers chose a very specific vibration machine for this study that produced peak to peak accelerations of only 0.2 g. Normally it would be very difficult to create a blinded situation where participants are unaware whether they were using a vibration platform or not. In this case because the vibration were so tiny, they were able to create a situation for the controls so that a barely minimal perception of vibration existed.  

This study used a number of statistical tools that make interpretation a bit more difficult. Since the exercises were performed at home, compliance to the protocol of standing on the machine varied quite a bit and this had to be corrected for.