I remember seeing this in Beatles Bubblegum packs - 5 cents in 1964. A horrible flat piece of hard gum came wrapped with baseball card-style trading cards of the Beatles. The caption for this one was something like, "here's what they would look like as normal lads" (again, circa 1964). The trading cards must have lasted until about 1965, since I remember seeing movie stills from Help in that format.
I have found it helpful to do the stretching exercises my physical therapist recommends. Do some core strengthening exercises, such as the ones highlighted at The Mayo Clinic. By keeping your core strong, your back won't put itself in a position to cause that sciatica pain you are having.