[En Sabah Nerd]

Sometimes I find that happenings in the rest of a building can make your toys lose standing. Like I have my set up on the second floor of my home, so sometimes the slamming of the front door or what not down stairs can mess with my less than greatly stable figures. I use NECA bases on those who worry me no matter how stable they seem (just small feet by design or loose hips type of stuff). I don't know how deep your shelves go, but maybe push those figures back some so even if they tumble they won't actually take the fall. For my NES Predator I have his feet as if he were leaning forward but his hips as if were leaning back, it's minimal and makes it look just kinda like he's crotch thrusting but he doesn't fall anymore and he doesn't use a base.