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.