 He likely got it from a Big Bill Broonzy recording "Rockin' Chair Blues" from 1940 using the phrase "rock me, baby".The phrase "like a wagon wheel" is used in the 1939 Curtis Jones song "Roll Me Mama" that includes the lines "Now roll me over, just like I'm a wagon wheel" and "just like I ain't got no bone".He re-recorded it in 1963 as "Roll Me Over", with some of the lyrics.