I've seen all kinds of click bait and "top ten movie trivia" lists claiming that Billy Bob Thornton put crushed glass in his shoes during filming the movie Sling Blade to give his character a more authentic look to his shuffle of a walk. It is cited as a case of extreme method acting which is not uncommon. While I don't necessarily disbelieve the claim, I can't find anything from Billy Bob directly claiming this. Its all unofficial trivia lists without a source. So my question is where did this trivia originate and is it true?
Yes, according to this MentalFloss article
- THORNTON PUT CRUSHED GLASS INSIDE HIS SHOES.
It gave him Karl’s famous limp.
Also corroborated by Chron (An independent Austin, TX newspaper) in this article
It hurt to play Karl Thornton told James Lipton on "Inside The Actor's Studio" that playing Karl was physically painful. His face had to be contorted and Thornton put broken glass in his shoes to get Karl's tortured walk down
Finally, Esquire in the UK posted the following article
Billy Bob Thornton Thornton took some extreme steps indeed for his role of a partially handicapped man in the sleeper hit Sling Blade. In an effort to maintain the consistency of his character’s memorable shuffle throughout filming Thornton placed real crushed glass inside his shoes, resulting in a painful limp. He was repaid with an Academy Award nomination for his pains. Unlike Lewis though he didn't get the gong - which must have been devastating.