elbow bump vs ulna

elbow bump

noun
  • A hit to the elbow; also, an injury to the elbow caused by such a hit. 

  • A hit or jab made with the elbow. 

  • The touching of elbows between two people, sometimes as an alternative to a handshake, fist bump, or other form of contact when attempting to avoid the spread of germs. 

ulna

noun
  • The bone of the forearm that extends from the elbow to the wrist on the side opposite to the thumb, corresponding to the fibula of the hind limb. Also, the corresponding bone in the forelimb of any vertebrate. 

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