I'm 64 and have arthritis in my knees, hips, spine and hands. I had a bad shoulder, too, but that was sorted by keyhole surgery a couple of years ago. I rarely have a soak in the bath these days because getting out is so difficult (I have to do the all fours thing, like a PP - it's not a pretty sight).
I've also got what may turn out to be some damage to one of the ligaments in my knee (been waiting for an MRI since before Christmas, now on hold because of lockdown, despite it being done at a private medical imaging company with an NHS contract, not at a hospital) and it gives way from time to time. I'm getting really paranoid about coming downstairs, as that's when it seems to do it the most. I get really frustrated by this, as it means I have to hang on to the banister and can't safely carry anything that needs too hands.
A couple of months ago, my knee gave way coming down the front steps and I came within a gnat's cock of faceplanting the lawn. Thankfully, my ample norkage hit the ground before my face and absorbed most of the impact.
DP now refers to my tits as airbags. 
And I hate, absolutely hate, the trouble I have undoing bottles, jars etc. It's so utterly frustrating!