Why would a State (North Carolina) not allow rails on the residents beds in assisted living?

One of the residents at my mothers facility has stitches in her leg due to falling out of bed (she falls out a lot) I'm told that the state of North Carolina will not allow rails on any of the beds . How do you take a senior a large senior at that, and expect them to say in a single bed? My mother will only sleep in a chair and I don't have to worry about this now but I know soon she will have no choice (her knees are locking up and she has no cartilage between the bones she will be bed ridden) In most of the semiprivate room one of the beds has to be placed against an A/C heater unit this leaves the perfect cubby hole to get wedged in. Maybe I'm not thinking straight but I don't see the logic.