well done! - combining my promenade question with an arthritis discussion!!
In case this comment fails for the fourth time, i'll keep it brief.
Have you had a scan which shows this arthritis? your comment makes it sound like a "at your age it must be arthritis" diagnosis.
Nurofen plus is the best i've found for joint pain relief, but it can be hard on the stomach.
glucosamine works but it's more a preventative than a cure.
keep exercising unless the pain is too severe to allow proper movement. It's vital to keep muscles strong as they stabilise the joints.
I could say much more, but it might not post. >
On the promenade thing - i think i've solved my problem - i was coming out fractionally too late, not getting my weight properly over my foot on 3&, and this caused me to rush into the following figure.
Inertia energy and movement? One area is the use of lowering to create flight (energy of movement horizontally) and of course the opposite - rising to cancel movement and to hover.