HOW: Begin standing with one foot flat in front of you and the other behind you with your toes pushing into the ground. Maintain that position as you put both arms straight out in front of you at chest height. From here, rotate your upper half to one side and return to the starting position. Alternate to each side for the prescribed amount of reps.
FEEL: You should feel a stretch in your mid back.
COMPENSATION: Keep your hips and feet facing forward as you bend to each side. Keep your arms up in front of you the whole time.