The cable external rotation strengthens and stabilizes the entire shoulder region while emphasizing the rotator cuff. The exercise also improves mobility of the shoulder joint.
Stand next to an adjustable cable machine with your feet shoulder-width apart. With the D-handle attachment positioned at chest height, grab the handle with the hand farthest from the machine, keeping your elbow tight to your side.
Rotate your shoulder to bring the handle across your body, keeping your elbow stable and tight to your side. When your forearm is straight out at a 90-degree angle from your stomach, pause and then reverse to return to the starting position.
Use a slow, controlled pace throughout the movement.