From the Mayo Clinic--not that helpful

Whole body vibration training: An effective workout? - MayoClinic.com

Whole body vibration also may have a role beyond sports and fitness. Some research shows that whole body vibration, when performed correctly and under medical supervision when needed, can:

• Reduce back pain
• Improve balance in older adults
• Reduce bone loss

Still, if you want to lose weight and improve fitness, enjoy a healthy diet and include physical activity in your daily routine. If you choose whole body vibration, remember to do aerobic and strength training activities as well. And because whole body vibration can be harmful in some situations, check with your doctor before using it, especially if you're pregnant or have any health problems.