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 10 of 10 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 10 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