Clownboy, there are lots of good tutorials on the forum using the shiatsu massager for a grave grabber, grabbing zombie or similar prop and I have built several but I didn't find any using a shiatsu massager for something like a standing zombie. However, I did find this one by CycloneJack using a wiper motor to power a standing swaying zombie that I thought was pretty cool.
By the way I have seen severl posts over the last couple of years asking where to find shiatsu massagers. I have several and I found them all at local thrift stores. The sell for around $4 each. Be sure to test them at the store before you buy them.