...in the "answers" section on the Polaroid Web site, the company says that shaking photos, which once helped them to dry, is not necessary since the modern version of Polaroid film dries behind a clear plastic window.
The image "never touches air, so shaking or waving has no effect," the company said on its site. "In fact, shaking or waving can actually damage the image. Rapid movement during development can cause portions of the film to separate prematurely, or can cause 'blobs' in the picture."
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.