So, ofTroy, if we think deeply about roots, a speech impediment is really a veiled way of saying one has put one's foot into one's mouth? And also something could be expedient--so maybe a speech expedient would be one's ability to ameliorate our speech impediments, hmmm?

And, to add to tsuwm's centipede, can't overlook the millipede...
Oedipus (It means something like crippled or wounded foot)
Now what about octopus? 8-what?
And paddleboats...
And pedal-pushers...
And pedestals...
"Put the pedal to the metal."
"Walk a mile for a Camel."
"These Boots Are Made for Walkin'"
"Shoe" by Jeff MacNelly
Santa fills stockings, and in some places, shoes...
Then there's the great Romantic composer, Franz Shoebert...
Shoe horns are blown by heels.
Athlete's foot
Foot - length of 12 inches
"Deadman walking" (very sad to consider, really)