That was my reaction, too. Old people in the US certainly aren't known for their knee/back virility.

Hell, the top Reddit comment on a recent image of an adult woman sitting on her knees was "my knees and back are killing me just looking at that!" with hundreds of people weighing with their stories of bodily problems and how they can't even jog. Presumably a demographic much younger than what we're talking about.

I remember thinking "wow, we are dying."