When we think of a “mobile” pelvis, many images come to mind! When we are referring to a “mobile” pelvis in pregnancy, we are speaking about the sacrum which has been called ‘the door of birth’. A mobile sacrum allows the door to open and the birth of the baby follows. The sacrum is a large wedge shaped vertebra at the lower end of the spine. It forms the solid base of the spinal column where it intersects with the hip bones to form the pelvis. The sacrum is a very strong bone that supports the weight of the upper body as it is spread across the pelvis and into the legs. Developmentally, the sacrum forms from five individual vertebrae that start to join during late adolescence and early adulthood to form a single bone by around the age of thirty. It can be felt externally near the base of the spine.
Supporting the range of motion via sacral pressure, sacral movement utilizing a support such as a tennis ball, heel of the hand, or via the mother’s rocking movements, etc allows the sacrum to remain mobile and function as it should not only in pregnancy but also in labor.
While in labor, the baby navigates the pelvis as it opens to accommodate its passenger. When the sacrum bulges outward, we know that the sacrum is\ mobile. This happens most frequently late in labor, but the mobility actually can be accommodated during pregnancy through body work gently performed on the pregnant mother. This body work may take many forms such as chiropractic care, massage, joint alignments, sacral/cranial therapy, etc. The mother can participate during pregnancy in assisting her body to enjoy a full range of motion via gentle pelvic tilts, walking, hip openers, calf stretches and flat footed squats with an anterior pelvic tilt.
Preparation before labor begins is a gift woman give to themselves to greatly enhance the body’s own mechanisms for navigating a baby through the pelvis, provide less discomfort in pregnancy and labor, as well as position the labor to be effective with many reports of shorter labors.
Excerpts taken from Gail Tully’s October 2018 Spinning Babies Newsletter. For additional information regarding this subject and many others, please go to spinningbabies.com.