Those are great if you can wear stilts, which I can't (well, I did when I was a kid but I don't have great balance). What I'd like is just something small that makes my step bounce: kids get to have those little roller balls in their sneakers. Why can't I have a pair that just lets me jump a little bit with my step? It would make running and playing so much fun.
It'd be useful for me on mountain descents as well. I really love steep descents on snowshoes because the landing is so soft. Ice/rock descents hurt. Having a little spring at the bottom of your stride would go a long way to saving the knees.
Trekking shoes have a device to absorbs the shocks, which is usually a gaz or gel layer inside the sole. Unfortunately, this cannot absorb much, since a thick sole would reduce the stability of the foot. By the way, always walking with shock absorbers has bad physiological consequences on the feet and knees.
I think the best way to protect the knees, aside from soft snow and screes, is to lower the body when walking down, and absorb the shock using the thighs' muscles.
More commonly, walking down stairs is a known knee-killer. This kind of product could be extremely viable for people who do a lot of walking at work – e.g. nurses, anyone in the hospitality industry, beat cops, etc.
I remember "moon boots" advertised in Boys' Life when I was a kid, that promised something like this. So I googled a bit and found https://www.bounceshoestore.com/ , is that sort of like what you had in mind?
