Exercise Ball Crunch

Setup
Sit on exercise ball. Walk forward on ball and lie back on ball with shoulders and head hanging off and knees and hips bent. Gently hyperextend back on contour of ball. Place hands behind neck or beside head.
Movement Instructions
Flex waist to raise upper torso rolling shoulders up and keeping chin pointed to the ceiling. Return to original position. Repeat.
Comments
Movement can be made easier by positioning ball higher up the back or exercise can be made more challenging by positioning the ball lower on back and hips or adding additional weight.