I am infinitely grateful that I can still bend in half at the waist and reach something on the floor without needing to bend my knees due to all that gymnastics and trampolining that I did as a child/teen/YA. This means that I am able to put the cats' food bowls on the floor and pick them up without the agony that bending my left knee would trigger. Agony. PainCount = 9. Sadly walking up and down the stairs to feed them is not helping that pain level. I am reduced to taking one step at a time and only bending my right knee, keeping my left leg locked straight. Unfortunately this is aggravating the pain in my right hip but, currently, that pain is much less intrusive than the agony in the left knee and so that is the plan at the moment. if that pain gets much worse I will be reduced to shuffling up and down the stairs to/from the kitchen on my backside (one flight of stairs down and again back up) and any doorbell-ring will be ignored (two flights of stairs down and again back up).