Popsugar Health & Fitness Workouts Are Crunches Bad For Your Back? The Reason You Should Stop Doing Crunches, According to an Expert 10 July 2018 by Tamara Pridgett View On One Page Photo 9 of 10 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 TipsBack PainCore ExercisesInjury PreventionWorkouts