not to do with motion so much as suspension. i always thought that the muzzy's apartment set was a little precarious to be hung from the rafters.
at my high school's theater i always dread putting on shows since they have no set movement method(the school dropped it from the plans along with the fly system and the dressing rooms to make it "cost effective") in the stage other than having stage hands run out with the lights dimmed. recently i flat out offered to pay for a turntable and was told it was "unneccesary and dangerous"....sorry for threadjacking, end of rant
"Grease," the fourth revival of the season, is the worst show in the history of theater and represents an unparalleled assault on Western civilization and its values. - Michael Reidel