Chiropractors are constantly trying to stay current with the never-ending information that is generated in the scientific research. Here we see Vert doing just that, only he’s doing it in an X-Rated Adult Spine Book Store! His eyes widen in amazement has he stares at a page in 101 X-Ray Positions. By his side sits The Joy of X-ray. Note the sign hanging by the door: “No One Under Risser 5 Permitted.” [Risser’s sign is a radiographic marker of skeletal maturity — grade 5 being fully mature — see the “Puberty” cartoon for another joke using Risser’s sign].
For more background on this cartoon see the Ideas chapter in Vert’s Story