constrain vs truss (up)

constrain

verb
  • To force physically, by strong persuasion or pressuring; to compel; to oblige. 

  • To keep within close bounds; to confine. 

  • To reduce a result in response to limited resources. 

truss (up)

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