On foot; walking. Also seen as "on shanks' pony" or "on shanks's pony." A reference to the shank—the lower leg between the knee and the ankle—and the historical use of ponies or horses for travel. My bicycle fell apart three miles away from home, so I had to go the rest of the way on shank's pony. Unfortunately, with the sedentary lifestyle many lead today, fewer and fewer people go anywhere on shanks' pony.