Neil, your progress is astounding. While I progressed from hybrid to road bike on the trainer, I had developed a severe fear of falling that kept me off the bike outdoors for a lot longer than I planned. Although, by 7 months post left knee replacement, well, I think we've seen my jump off the ATV plenty by now. While the 3' drop didn't hurt, it helped me with my fears of falling.I do know, when my other knee needs replacing, I won't be afraid or hesitate. I still know its not original, but I don't give it much thought from day to day. Its part of me now, and its little clicking when I shake it while dangling it is sort of amusing as those that hear it cringe.
With my back injury, I'm just not pushing the envelope at all. I've healed well, but I want to be painfree in my old age. So, no coloring outside the lines. The things I will do, have been approved by my surgeon and therapist, even though I'm done with therapy. Having him as a friend is proving helpful.