Standing poses easily morph into forward bends. Forward bend poses can be standing or sitting poses. Forward bends stretch the back of the body and are essential for lengthening the muscles of the back, legs, shoulders, neck, and spine. Forward bends also activate many of the internal organs as the front of your body folds over itself. That same folding inward can also help the mind focus inwardly for greater relaxation and a reflective, inner-gazing state.
Great collection of yoga back exercises.