Anchor a band at waist height. Stand sideways to the anchor point with the working arm further away. Hold the hand while keeping a 90 degree bend in your elbow and your hand reaching across to the opposite side of your waist. While maintaining the bend in your elbow, rotate your arm at the shoulder until you can no longer rotate it. Slowly return the handle to the start position. Complete all reps with that arm, then switch arms, facing the opposite direction.