Ab Kickbacks - Men May 18, 2018 19:34 Main Muscle: Core, Quads Use ankle attachments. Begin in a straight arm plank position- back neutral, core tight. Crunch abs and bring knees forward towards chest. Jump legs to starting position. Repeat. Related articles Where do I get training videos? Bucket Toss Instructions Where can I get copies of BodyBoss Product Manual and Workout Booklet? Overhead Triceps Instructions Ab Twist Instructions