The shoulder joint is the most mobile joint in the body. It’s also highly relied upon throughout the day for lifting objects such as boxes and also for directing all of our hand movements. This ball and socket joint is also easily injured due to its wide range of motion.
The muscles of the rotator cuff secure the humerus (arm bone) to the shoulder joint via connective tissue. The muscles of the rotator cuff include the supraspinatus, infraspinatus, teres minor and the subscapularis. These four muscles and their respective tendons stabilize the humeral head into the ball and socket joint.
You can help to keep these important joints properly aligned and in a stable position by practicing good posture. Also by incorporating stretching you can help to reduce stiffness in the shoulders following hard exercise or after a long period of sitting in which the shoulders may have been hunched over.
Many exercises such as shoulder shrugs or front shoulder raises strengthen larger surrounding muscles such as the trapezius (upper back) or front deltoids which raise the arm once it’s lifted away from the body. However the finer muscles of the rotator cuff aren’t targeted with these exercises and can become injured by a wrong movement or poor posture and body mechanics.
It’s recommended to do external and internal rotation to strengthen the muscles of the rotator cuff (1). Here are two photos showing how to do internal and external rotation with the Gravity Ball. Use the lightest weight for this exercise and slowly move your arm in and out keeping your arm at 90 degrees, with your elbow close to your side.
Give this exercise a try to prevent injury in the shoulders, one of our most versatile and valued joints.