What is pelvic tilt with marching?

Pelvic tilt with marching

1. Lie on your back on the floor, with your knees bent and your feet flat on the floor. (Or you can lie on any flat surface, such as a bed.)
2. Tighten your belly muscles by pulling your belly button in toward your spine. Press your lower back to the floor. You should feel your hips and pelvis rock back. Try to keep the belly muscles tight while you do the exercise.
3. Slowly lift and lower one foot at a time, like you are marching.
4. Continue until you have done this 8 to 12 times with each foot.