Dumbbell Back Squeeze
I don’t know if this is the technical name (I’m not a personal trainer), but this exercise hurts so good! Stand with your feet together, knees slightly bent, holding a dumbbell in each hand. Assuming your body is a clock, bend your arms so that your left arm is facing 11 o’clock and your right arm is facing 1 o’clock. Keeping your arms at that level, squeeze your back muscles tight and move your arms back slightly. They won’t be able to go very far, but you should feel it working your shoulders and upper back