Long history of this practice. Going back to the late 1700s when the US Government chose to award a pension to a civilian light house keeper who was crippled during a attack on his light house by Indians. The only part of his body the Indians were able to hit was his feet as he took refuge on the second floor of the light house. Bows and arrows through the cracks in the floor boards. Source for this story is a old book written in the 1800s about the Pioneer Indian wars. Sorry no link and I don't recall the title.