Those 5 Flights Up

What does "can't managed" mean??

If you actually saw the movie you'd know that they in fact did go up those stairs without assistance and decided to continue to do it for as long as they remained healthy. I believe they were more concerned about the dog having to go up and down the stairs.

..*.. TxMike ..*..
Take a risk, Take a chance, Make a change. Kelly Clarkson - Breakaway

Their issue with the stairs wasn't how difficult they managed the stairs now but how they would manage them as they grew even older. This was mentioned more than once.

For a lot of older people, stairs (defying gravity) is harder than moving horizontally.

As somebody who has suffered with an arthritic hip (i recently had it replaced) i can assure you there is a big difference between walking on flat ground and climbing stairs.