You got me thinking there, Herbs. Around which axis* do the dead spin, when viewed length-ways from the side? I used to imagine them spinning around the x axis, which was an uncomfortable thought as the coffin, soil and neighbouring graves would be in the way. But if they spin around the y axis, as if turning on a spit, they can do that without leaving their coffin. z axis is right out, as apart from the same problems as the x axis, their heads might poke up out of the ground once per revolution. That would be weird.
*Did you see what I did there? Axis. Ha ha.