You'll be glad when you stop climbing ladders. I did it for 18 years, my knees got so bad at times I had to really use my arms to drag me up to the next rung.
I've been to the doctors many times, he sent me to a Podiatrist, who I now visit every 2 years, he fits me with foot instep supports, the theory is that they help "realign" my knees.
The best thing is go wfp - no more ladders.
Now after 5 years wfp, (mind you I am 56) I have permanent back ache, neck ache, carpal tunnel problems, chest pains too!

I won't be doing it for 15 years, I know that much, but it's bought me time.
