ball and chain vs impediment

ball and chain

noun
  • A heavy iron ball attached to a prisoner's leg by a chain as a means of restraint. 

  • One's wife, as a symbol of restraint. 

  • Anything that restricts one's freedom or opportunities. 

impediment

noun
  • Baggage, especially that of an army; impedimenta. 

  • A disability, especially one affecting the hearing or speech. 

  • A hindrance; that which impedes or obstructs progress. 

How often have the words ball and chain and impediment occurred in a corpus of books? (source: Google Ngram Viewer )