I meant to add to this yesterday - I've now received my gizmo and tried it out on Saturday during a rare dry spell. It works! No more staggering about like a drunken elephant and falling flat on my face among the dandelions.
As an aside, I wonder why it is so many of redevelop an inability to get up from kneeling? In OH's case, his knees are shot and he can't get down, never mind up again. But for me and many that I know, one day it wasn't an issue then the next, we were groping about for something to hold on to and trying to maintain a little grace and dignity as we wonder what the heck happened??