overextend vs overstrain

overextend

verb
  • To expand or extend to an excessive degree, especially to do so beyond a safe limit. 

  • To push a pawn too far, so that it becomes vulnerable to the opponent's attacks. 

  • To apply (a term) to too many referents, by overextension. 

overstrain

verb
  • To subject to an excessive demand on strength, resources, abilities, or the imagination. 

noun
  • excessive strain 

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