I haven't used this myself, but I'm 99% sure this is the harness I see used regularly in rescue for our one dog that has had to learn to walk due to a neurological issue and for other sick/injured dogs, after amputations and stuff.
They've been using these for a few years now and I've never heard any complaints from the humans or dogs. The volunteers that use them are all physically fit, so idk if it would be hard on someone less strong or able bodied.