My wife bought this to do some rehab exercises. She no longer needs it. Here's some info from the Bodyblade website:
Created by Bruce Hymanson, PT, Bodyblade® pioneered vibration and inertia training in 1991. With its patented design, it was created to address the deep dynamic stabilizers of the spine and to provide a stable platform for all other rehabilitation, sport performance training, fitness enhancement, and personal training programs; resulting in improved wellness, function, and muscle definition.
Bodyblade uses vibration and the power of inertia to rapidly contract your muscles up to 270 times per minute, stimulate your nervous system, and transform your body. Bodyblade will build your body from the center out to develop stability before mobility; providing you with a strong, well balanced, and functional body.