Most of us find ourselves in the very common "hunched over" (or protracted) posture on a daily basis. As I type this blog entry, I am very conscious of how my head is tilted forward to see the screen, stretching my posterior neck muscles, and how my shoulders are protracted and medially rotated so that I can reach the keyboard. As a result, my upper back muscles feel tight and overstretched and my chest muscles feel tight and contracted (in massage school we'd describe this distinction as "long tight" vs. "short tight" muscles).
Computer work can create this "hunched over" feeling, but so can other common activities such as cooking, gardening, writing, and reading. For many of us who find ourselves repeatedly in this protracted position due to our work, some extra care may be needed to help with the resulting tension and strain.
The first thing that helps with the tension we feel in our upper back and neck muscles (upper trapezius, levator scapula, rhomboids, etc.) is to relax them--to put these muscles in their shortened (softened) positions. In addition, the chest muscles (pec minor and major in particular) must help this process by opening up or stretching out of their contracted positions.
The example provided here is just one of the many ways to relax the back and open the chest.
After a period of computer work, creating art, or giving massages, I roll up a bath towel and set it behind me on the floor. I allow the towel to follow the contour of my spine (from my tail bone to my neck) slowly allowing my shoulder blades to drop to the floor and my rhomboid muscles to soften. I also take several deep breaths to help my muscles relax to their new position. I often feel a lovely stretch in my chest, too, and sometimes I feel a tingling all the way down to my fingertips. I feel that I am opening some energy meridians and stretching my fascia (connective tissue).
Take care that you feel no pain during this stretch and that you move from one position to another slowly. If you try this stretch, do let me know how it goes for you!