You sit on it all day. You fear it might be spreading. Stand up and take a few moments to work your BOOTY while at work.
Move 1) Place your hands on the back of your chair for balance. Reach left leg out directly behind you, pointing your toe.
Move 2) Keeping your knee straight, lift your leg just using your booty, without leaning forward. Don't worry, it won't go very high. Use your deep abs to keep from arching your back to lift your leg and to help you stabilize. Repeat 15 times at a fairly quick pace, then switch legs and do the other side.
Try to do this multiple times a day. It gets the blood moving in your seat.
And to see how NOT to do it,