External rotator cuff exercises are effective to build strength and flexibility in rotator cuff. Rotator cuff is a group of muscles on shoulder joint that are important for circular shoulder movement as used in throwing a ball. Regular rotator cuff exercise is necessary to improve strength and flexibility to prevent sudden injury risks and muscular strains. Shoulder is the most flexible joint in your body that needs strength and flexibility to perform a number of tasks regularly. External rotator cuff with toning tube allows you to activate your shoulders and increase the stability.