My body gets all stiff after sitting in front of the computer for too long. I call this 'Blogging Hazard" - The body is flexible. It is supposed to be flexible. You must be able to bend and reach that something you dropped on the floor. You must be able to zip the back of your favorite dress on your own. You must be able to reach that book you need to read at the top shelf.
These are simple activities. Nothing grand about them, you merely stretched out a bit. However, if there are difficulties in doing such simple motions, then you have to stretch your limits. You already need a stretching program.