
In Parts 1 and 2 of our series on How to Keep Your Shoulders Healthy, we discussed the importance of improving mid-back (thoracic spine) mobility and developing scapular stability. In this final installment, we discuss how to strengthen the muscles of the rotator cuff to prevent shoulder injuries—a serious concern for athletes in overhead sports such as tennis, softball, volleyball and baseball.
As previously discussed, the shoulder is a highly complex joint, consisting of three bones linked by a number of muscles and a web of ligaments attached to four interdependent joints. One joint in particular, the acromioclavicular joint—referred to as the rotator cuff—is commonly afflicted by injury. The rotator cuff is encircled by four muscles:

Collectively, the muscles of the rotator cuff provide dynamic stability for the shoulder, locking the head of the humerus into the cavity of the shoulder blade.
Rotator cuff injuries are particularly common among throwing athletes and recreational weightlifters, due to overuse or lack of strength. If a rotator cuff muscle is enflamed or injured, it is at risk for impingement and potential tearing. Also, an injury alters the natural function of the shoulder, which can have other damaging effects to the joint.
To prevent rotator cuff injuries, you must regularly perform exercises that directly engage these muscles. It's important to keep them strong to maintain shoulder stability and avoid time on the disabled list.
Rhythmic Stabilization Drill
Sets/Duration: 2-3×15-45 seconds
Side-Lying External Rotation
Sets/Reps: 2×10-15 each side
Constant-Tension Scapular Raise
Sets/Reps: 2×8-10
Photos: zimbio.com, orthoinfo.aaos.org
Joe Giandonato, MS, CSCS, is the head strength and conditioning coach at Germantown Academy in Fort Washington, Pa. He has authored numerous articles on a wide variety of topics, including injury prevention, nutrition and improving athletic performance.