Starting Position: Lie flat on your back on a mat in a bent-knee position and place a small pillow, rolled-up towel or foam pad under your head. Pull your shoulder blades back and down without moving your ribcage or low back. Try to hold this engagement throughout the exercise. Hold a light dumbbell or weight in one hand. Press that arm toward the ceiling, keeping the wrist straight and shoulder blade in contact with the mat. Place your opposite arm alongside your body.
Engage your abdominal muscles to stabilize your spine and keep the abdominals contracted throughout the exercise. Gently exhale. Rotate your trunk and legs slowly towards the arm placed at your side. The dumbbell arm does not move at all. The arm stays straight and shoulder blade stable and flat to the mat. Continue to rotate until shoulders are almost stacked upon one another. This places a significant stretch and increased load into the upper shoulder. Keep the shoulder stabilized and avoid any arching in your low back that may occur with the rotation. Bracing your abdominal muscles will help prevent this.
Pause momentarily then slowly return back to your starting position.
Perform 5 - 10 repetitions at a slow, controlled pace. Repeat on the opposite side.
Exercise Variation: If a light dumbbell is not available, perform this exercise without any resistance or with any weighted device. The exercise complexity is increased by holding a kettle bell that has an "offset center of mass."
To maximize the benefits of this exercise and reduce the potential for injury, it is important to stabilize the shoulder blade and carefully control the movement. Follow the instructions provided carefully