put one's back into vs put one's shoulder to the wheel

put one's back into

verb

  • Synonym of strive: to apply oneself. 

put one's shoulder to the wheel

verb

  • Synonym of strive: To work hard, to complete an activity with one's complete effort and focus. 

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