put one's back into vs seek

put one's back into

verb
  • Synonym of strive: to apply oneself. 

seek

verb
  • To try to acquire or gain; to strive after; to aim at. 

  • To try to find; to look for; to search for. 

  • To try to reach or come to; to go to; to resort to. 

  • To navigate through a stream. 

  • To ask for; to solicit; to beseech. 

  • To attempt, endeavour, try 

noun
  • The operation of navigating through a stream. 

How often have the words put one's back into and seek occurred in a corpus of books? (source: Google Ngram Viewer )