Infiltration.org is the online companion of the paper zine about going places you're not supposed to go.
The segment on getting into the Royal Park Hotel reminds me of sneaking into the Concord Hilton as a teenager. We would slip in through a side door and prowl the floors looking for those little marmalade jars that room service delivers. Then it was onto the roof overlooking the satellite dish where we would open the jars and drop the jam onto the dish from 11 floors up. Good Times.
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.