impulse vs shot in the arm

impulse

noun
  • A wish or urge, particularly a sudden one prompting action. 

  • A thrust; a push; a sudden force that impels. 

  • The integral of force over time. 

verb
  • To impel; to incite. 

shot in the arm

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

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

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