How can I improve mobility in my back?

One of the easiest ways to improve mobility in your back is to perform self-myofascial release with a foam roller on your thoracic spine (mid and upper back region).  Foam rolling can help to reduce tension in the mid and upper back muscles and improve the range of motion of the thoracic portion of the spine.  The seated positions most people are in for prolonged periods of time have a tendency to cause slouched posture and rounded shoulders.  This posture leads to decreased mobility in the thoracic spine, which should be the most mobile part of the spine.  If the thoracic spine develops less mobility, over time the body will compensate by creating more motion in the lower back and neck than should there be, increasing stress to those areas as well.  Perform the thoracic spine foam roll by following the technique described below. Lie face up on the floor with a foam roll underneath the mid/upper back. Next, place the hands behind the head and let the elbows fall out toward the floor while keeping the head relaxed but supported.  Last, raise the hips off the floor while slowly rolling back and forth and applying pressure on any tender spots for at least 30 seconds.