Shoulders are a very complex area of our bodies because they are highly flexible joints that move in many directions. It's important to train them with appropriate exercises, like this one, designed to improve joint stability and muscular balance.
Sit upright in a sturdy chair (you can also perform it standing upright). Grasp a dumbbell in each hand. Begin with your upper arms hugging the sides of your torso, elbows bent at a 90-degree angle and tucked into your waist. Start with the ends of the dumbbell touching at the center of your waist.
Keep your upper arms pressing firmly against your torso as you externally rotate both your arms out to the sides. Be sure you make this movement happen at the shoulder joint while maintaining a bend at your elbow with your forearms parallel to the floor. Pause at the furthest point of the rotation. Slowly return your dumbbells to the center. Repeat for 12 repetitions. Rest a few seconds, then repeat two more sets of 12 reps.
Voight is the creator of a line of fitness DVDs, including "Sleek Essentials."