Primary Muscle Group: Waist and sides
Muscle Groups Worked in This Exercise:
Preparation: Stand tall with your feet directly under your hips. Place both palms on the ball.
Breathing: Exhale as you raise either arm and inhale as you return to start position.
Execution: With your palms on the ball, roll the ball forward as you bend forward from the hips. With your right palm on the ball, exhale and raise your left arm toward the ceiling. Let this movement open your chest and twist your spine. Keep the weight equal on both feet. Hold this for 30 seconds, then inhale and return to start position. Exhale and raise your right arm toward the ceiling and repeat. Hold each side for 30 seconds.
Comments: Since you are doing this spinal twist with your hands on the ball, you can focus specifically on rotating your spine and deepening your stretch.
Here are a few suggested alternative exercises:Ab CrunchAb Crunch - MachineAb Crunch ObliquesBall Crunch TraditionalDouble CrunchDumbbell Side BendsKneeling Cable CrunchKneeling Oblique TwistLateral Bend with Barbell