Sitting does not allow for much variation in back posture . Static back postures will create muscle fatigue and strain. Further, a chair that does not provide proper lumbar support will require the back muscles to solely maintain the back's neutral posture, also creating muscular fatigue. These stretching exercises will relax the back muscles relieving tension and fatigue.
While seated or standing, interlace fingers behind head. Pull shoulder blades toward each other until you feel tension through your upper back. Hold position.
2. Shoulder Roll
Start with back and neck in a neutral posture. Slowly roll shoulders forward three times in circular motion. Repeat exercise rolling shoulders backwards.
3. Chest Stretch
Move to a corner of the room. Face the corner and place each forearm on a wall. Place one foot in front of the other and slowly stretch by leaning forward towards the wall.