I have one more thing to remember now.
First thing I think of before leaping from bed. I rub them, muttering fond endearments and encouraging words.
It came without warning but I was slow to realise anything amiss, ie walking down each stair a foot at a time and holding a banister. It may have been wilful blindness - I'm good at that - or just the fact that early in the morning I can fulfil basic tasks like making tea whilst my brain remains asleep.
Gradually I realised I shouldn't be walking like an old man. Not for another fifty years at least!
What was happening?
Why did my knees ache after a good night's sleep, or on standing up from the desk top?
It was time for Dr. Google. It told me I had a problem with 'the knee cap (patella) and how it moves.' Well, thank you. I'd already figured that one out. But then it went on to tell me more than I wanted to know:
"The kneecap is a small bone, shaped like an upside down triangle which sits in the patella groove at the front of the knee and glides up and down as the knee moves. Huge forces go through it with every day activities. As a result, the back of the patella is lined with the thickest layer of cartilage in the whole body as it is designed to withstand massive compressive forces.
Knee pain going down stairs is not surprising when you consider that the force going through the patella is 3.5x body weight when you come down the stairs (normal walking only puts a force of 0.5x body weight). That means for a person weighing 120lbs, when they come down stairs, a force of 420lbs goes through the kneecap which has a contact surface area of only 12cmsq."
Well, when I read that, I thought 'Respect'. Fondled each knee in turn and considering perhaps it was time to lose weight. But even halving my 210 Ib would still amount to 367.5 lb going through each of my small but precious 12cmsq knee caps. If significant weight-loss seemed pointless, losing a mere stone seemed even more so. (This is how the mind of a reluctant dieter works.)
Well okay. I'd learnt something, time to learn more. The question now was whether it was simple damage to the meniscus caused by intense athletic activity. Reluctantly I discarded that as unlikely. Two options remained: Osteoarthritus, or Housemaid's knee. I liked neither of those. One cast the shadow of approaching apocolypse, the other seemed merely ignonimous. Housemaid's knee. Never!
I read more. One doctor used the analogy of a rusty door, opening and closing ever more smoothly with use. At rest the joint fluid is soaked up by the cartilage like a sponge soaking up water. When the joint is used the cartilage is squeezed and fluid lubricates the joint. However, in an arthritic joint less fluid and diminished cartilage makes for a 'rusty door'. Use brings some respite, over-use makes it worse.
There is still hope. It may be gout. I like the idea mellowing into the crusty and obstreperous, but then again I'd have to give up alcohol and cheese. Even Housemaid's knee would be better than that.