I play Second Life. People ask me what is Second Life? I try to explain how it is a 3D environment where you can build anything and be anything. It is hard to explain. Luckily, several fine folks have made some short films illustrating exactly what Second Life can be.
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.