I'm 21+4 and getting quite bad sciatic pain on the left hand side of my back. I have an office job, pretty much sitting at my desk all day. I'm lucky enough to have an orthopedic chair (because I used to suffer from back/sciatic pain a lot, luckily not anymore but it comes back when I'm pregnant!) so I know I have good posture while sitting, but it's not making the difference at this point.
I know about taking frequent breaks to get up and move around a bit, but are there any other things I can do to be more comfortable? At this point I'm finding it really hard to concentrate on work because of the pain (the pain is bearable, not excruciating or anything, but very distracting).