Popsugar Fitness Workouts Are Crunches Bad For Your Back? Crunches Are Bad For Your Back — Here Are 10 Ab Exercises to Do Instead January 21, 2019 by Tamara Pridgett View On One Page Photo 9 of 11 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 9 Circling Plank Begin in an elbow plank with your forearms resting on the top of a ball. Keeping your core strong and your body still, use your arms to roll the ball in a small clockwise circle. This completes one rep. Previous Next Start Slideshow Fitness TipsWorkoutsCore ExercisesBack PainInjury Prevention