So it can be done. Why wouldn't it work on a force user? Jedi can be pushed against their will by the force, and even if they could theoretically stop someone snapping their spine, are Jedi really going to be able to react fast enough to a seemingly instantaneous application of force? Or are they just expected to be holding all their vital parts stationary [i]somehow[/i] with the force?

Also, is there any way for an average joe to not get his heart popped? Or is every non-force user just so much chopped liver within however many feet of a smart force user?