We rely on strong core muscles to stabilize the spine and help prevent injuries during everyday activities and sports. This exercise requires your abs to stay tight against the movement of the arms and legs.
Sit upright on a flat, level surface with your knees bent and feet flat on the floor. Place a small, inflatable ball or firm pillow behind your waist. On an exhalation, create a C-curve with your spine, pressing the back of your waist against the ball. Maintain pressure against the ball as you bring your arms out to the sides and rest your hands on the floor. Pause for 2 seconds.