obstruction vs shot in the arm

obstruction

noun
  • Something which obstructs or impedes, either intentionally or unintentionally 

  • The act of obstructing, or state of being obstructed. 

  • The condition of having the natural powers obstructed in their usual course; the arrest of the vital functions; death. 

shot in the arm

noun
  • An injection of a drug into the arm, whether for medical or recreational purposes. 

  • A stimulus; a boost in energy, morale, or well-being. 

How often have the words obstruction and shot in the arm occurred in a corpus of books? (source: Google Ngram Viewer )