User blog comment:Uskok/Dead Men Tell No Tales Official Trailer/@comment-4693709-20170303015944/@comment-1984959-20170303185341

If you want a comic-related reference: Theatricality and deception are powerful agents. In other words, maybe Barbossa uses it to fool anyone who thinks he's just an crusty old pirate until he fights back. Don't forget that Barbossa used his crutch as a weapon against Blackbeard.