Since my complaints about my back elicited both sympathy and, sadly, stories of your own back troubles, I think I owe it to my readers to report that I seem to be on the mend. Not yet able to resume my morning walk, but no longer as desperate as I felt the first day. Walking upright is not anatomically natural, and I suspect proto-humanoids have been paying the price for several million years.
On another matter entirely, I have found during this unhappy time that it is completely impossible to make a cat feel guilty or even sympathetic. Dogs yes, but not cats. I suspect there is a deep life lesson there, but I choose not to heed it.