manacle vs road block

manacle

noun
  • A fetter, a restriction. 

  • A shackle for the wrist, usually consisting of a pair of joined rings; a handcuff; (by extension) a similar device put around an ankle to restrict free movement. 

verb
  • To confine with manacles. 

road block

How often have the words manacle and road block occurred in a corpus of books? (source: Google Ngram Viewer )