put one's back into vs wrestle

put one's back into

verb
  • Synonym of strive: to apply oneself. 

wrestle

verb
  • To struggle or strive 

  • To take part in a wrestling match with someone 

  • To move or lift something with difficulty 

  • To fight. 

  • To throw a calf etc in order to brand it 

  • To contend, with an opponent, by grappling and attempting to throw, immobilize or otherwise defeat him, depending on the specific rules of the contest 

noun
  • A struggle. 

  • A wrestling bout. 

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