Rotational exercises can strengthen the small muscles that help stabilize the shoulder, known as the rotator cuff. While these muscles are worked to a degree through training, it is easy to develop an imbalance and this needs to be corrected. Consult your physician before beginning any diet or exercise program.
The Rotator Cuff
The rotator cuff is comprised of four muscles: the supraspinatus, infraspinatus, teres minor and subscapularis. The supraspinatus and subscapularis are classed as the internal rotators, and the infraspinatus and teres minor are classed as external rotators. Internal rotators pull your arm in toward your body and help with rotating your arm so your palm faces in. External rotators do just the opposite. The internal rotators are heavily stressed during many forms of conventional training, but unless you are practicing Olympic-style weightlifting, the external rotators do not get much work, which can lead to an imbalance, pain and injury.
Training the Internal Rotators
Internal rotations are performed using a cable attached to a weight stack. Holding the handle at waist level with your elbow at your side and your forearm out away from your body, rotate your arm until your forearm crosses your waist. Keep your forearm parallel to the ground at all times, and never jerk the weight. You should be able to perform the exercise smoothly and without twisting your body for 20 repetitions.
Training the External Rotators
External rotations are done in the same manner as internal rotations, only you start with your forearm across your body and the weight on the same side as your non-lifting arm. An alternate method involves sitting with your upper arm firmly supported while straight out to your side. Holding a light dumbbell in your hand, bend your elbow until your forearm is perpendicular to the ground. Lower the dumbbell slowly until your forearm is parallel to the ground, then return to your starting position. The weight should be one you can easily control for 20 repetitions.
Scapular retraction is when you pull your shoulder blades back against resistance. This can be done using a resistance band and helps stabilize the external rotators. Face pulls achieve scapular retraction and are done by using a rope extension in both hands attached to a cable stack. Lean back slightly by arching your back, then smoothly pull the handles back while your arms remain in line with your shoulders. The weight should be one you can handle for 20 repetitions.