Foot odor (or foot odour) is a type of body odor that affects the feet of humans and is generally considered to be an unpleasant smell.
https://en.wikipedia.org/wiki/Foot_odor
Concept art Smelly feet Bad knees
"For all our failings, despite our limitations and fallibilities, we humans are capable of greatness."
Robot Leg Concept
Concept art Smelly feet Bad knees