Pelvic Rocking is a safe way to keep stomach muscles tone. In addition it helps to relieve a sore back by stretching the lower back muscles. The rocking motion helps stimulate the digestive system which helps lessen constipation. The movement also realigns the uterus, which means if you do this before bed time you can sleep longer before you need to empty your bladder.
As you progress in your pregnancy and your baby grows, there is less room for movement. You will notice what used to be kicks and jabs become rolls and wiggles. Modern life has women sitting for most of the day, which limits pelvic flexibility and the baby's ability to navigate the best position for labor within his tight quarters. Pelvic rocking helps your baby get into the best birth alignment by stretching and opening the pelvis and releiving pelvic congestion by changing the direction of gravitational force.
How to do it
While on hands and knees, tilt your pelvis under by contracting deep abdominal muscles. While you are learning, try to pay close attention to the abdominal contraction. This will prevent you from trying to tilt your pelvis by arching your back. When it is done properly, the movement is very small and your back should stay relatively flat.
Pelvic Rocking can be used as part of a regular pregnancy exercise routine, and can also be used in "backache emergencies." Pelvic Rock as necessary throughout the day to prevent a sore back, or when your back begins getting sore.