Upper body supported back exercises have great value for those who struggle with postural issues. Setting up your back to be worked with support allows for a full range of motion. These are great as a warm up or as a work set.
Start by sitting on the ground beside the bench or box, with the weight in your lap. Pushing through your heels and squeezing your glutes, raise your upper back and shoulders up on the bench. You should be able to make a perfect table top position. Raise the weight straight up over your chest and slowly extend your arms up over your head, stretching your lats. When you feel a full stretch, squeeze your lats bringing the weight back to starting position.