Lie on your back with your knees bent and feet flat. Keeping your shoulders pressed on the floor, roll your tailbone up into the air, then lift your vertebrae off the floor one at a time until only your feet and shoulder blades touch the ground. Holding this position, straighten your right leg, keep your knees parallel with each other, and hold. Place your hands on your hips to steady your pelvis. Hold for 10 seconds, then bring your leg up toward your chest and straighten. Do 10 reps on each side.
For the Shake:
Lift up to the bridge position (at left), straighten one leg out, and bring it out to the side without moving the pelvis. Return your leg to center and repeat eight times. Repeat on other side. Focus on relaxing your shoulders and keeping your pelvis still.