bowing vs flexion

bowing

noun
  • A bending. 

  • A technique for using the bow on a string instrument such as a violin. 

  • The act of bending at the waist, as a sign of respect or greeting. 

flexion

noun
  • The state of being bent or flexed. 

  • Deviation from straightness. 

  • The act of bending a joint, especially a bone joint; the counteraction of extension. 

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