I think OP is asking for any alternatives that are more fullproof than simply holding into a cane or walker. It can only take one stumble or slip and fall for someone at 80-90 to break a bone, never completely recover, and lose their ability live independently and be forced to go to a nursing home or other assisted care facility.

Though more intrusive to wear/use, I would imagine there are some bionic leg braces that could keep legs stable 99% of the time.

I don't think there's anything that could stop them from falling, but maybe it could warn them about how slippery the area is, based on the accelerations sensed by similar devices in the same spot. But I don't know of anything that does it.