Ball Leg Curl

Instructions

1. 
   Lie faceup on the floor with legs extended and heels on top of a stability ball. Keep hands at sides, palms down. Lift hips, forming a straight line from shoulders to heels; squeeze glutes at the top of the movement.
2. 
   Keeping hips raised and back straight, bend knees as you bring ball toward your body. Slowly roll ball back to start and repeat.