I often find in teaching prenatal yoga, that I have to adjust my instructions from the classic or traditional ways in which certain asanas are instructed. Part of this is because the body most of the yoga asanas were developed on was a male body, but some of this is also because some of the cues are outdated, and have become overused or over-instructed. The prime example? Tucking the tailbone!
I primarily encounter this instruction in postures like Tadasana, or Uttkatasana where we seem to have gotten the impression that our lower back should resemble a straight line, without any major angle from our sacrum and buttocks. Let me state right away, that this is not only physiologically unhealthy, but can be actively detrimental when we look into the changes the body goes through during pregnancy, and our drive to maintain body balance through these changes to reduce compression and discomfort.
Notice the angle of the pelvis in neutral
First off, a quick anatomy review. The spine is comprised of mirroring sets of curves, with joints that best lock together at a curving angle (NOT straight). The Lumbar (lower back), and Cervical (neck) curves arc towards the front of the body, while the Thoracic (mid-back) and the Sacral (sacrum) curves arc away from the front of the body. Where these curves intersect we find an angle as the curves reverse direction. The reason for these curves in the spine is to provide shock absorption for the spinal discs and internal organs as we move, run, and jump in our daily lives. Without these curves, the spine would be like a stiff stick, which if too much pressure is applied to, can snap rather than bend. Now, yes, when talking about the spine it is common to only discuss the 3 upper curves and ignore the sacrum, since by the time we reach adolescence the sacrum is a fused bone rather than articulating internal joints, but the curvature of that bone becomes crucial when we look at both how the pelvis finishes the support, and how the spine changes with the weight of pregnancy.
The pelvic bowl forms the final curve of the spinal shock absorption, and also allows the weight of the upper body to transfer into the lower limbs and the earth. Misalignment between the lower back and the pelvis at the sacrum (where the two articulate) leads to the load of the upper body being born by the muscles and connective tissues, rather than by the bones which were designed to hold the weight. This means greater muscle tension throughout the spinal column, but especially in the lower back lumbar spine) where the weight makes the transfer into the legs. The system is meant to be dynamic. Adjusting to changes in weight and center of gravity to allow for supported, and strong movement. Now add to this dynamic system the additional weight of pregnancy. The growing weight and expansion of the belly and breasts leads to a heavier load on the spinal column, as well as a gradual forward shift in the center of gravity as the belly grows. By the end of pregnancy, mom’s center of gravity may have shifted nearly 4 inches further forward. Without any compensation from the spinal column, the body would become top heavy and full term pregnant women would topple forward every time they attempted to move! Enter deepening spinal curvature, both to provide better shock absorption from the increased weight, and to rebalance the center of gravity into the pelvis and the legs.
image credit: https://mongoosebodyworks.com
So what does this have to do with the tucking the tail cue for Tadasana? Well if we think of the pelvis as the bowl intended to catch the internal organs and finish the spinal shock absorbing curvatures, tucking the tail shifts this bowl out of alignment. While our body will compensate in some way to re-find balance (our body is very smart and doesn’t want us to fall over), the shift will load another area of the body which was not meant to carry this weight. Usually I find this is either the lower back muscles, or their mirror group of the neck and shoulders. Ironically, the most common reason I hear for tucking the tail is to alleviate lower back pain. While the tuck may relieve it for a few minutes, chronically tucking will only exacerbate the underlying tension.
The abdominal container
image credit: https://www.researchgate.net/profile/Kate_Emerich
As if balancing our body’s weight into our bones wasn’t reason enough, there is an additional consequence of constantly tucking the tail. When put the pelvis in a posterior tilt we not only take the bowl out of alignment, we also take the muscle of the pelvic floor out of neutral. As renowned pelvic floor yoga teacher Leslie Howard often says “Your pelvic floor is strongest when in a neutral position.” This means if we spend all our time scooping the tailbone under, we lessen the ability of our deep pelvic muscles to provide support for our internal organs. For labor, we lessen their ability to develop tone and suppleness in preparation for birth. This results in tension and weakness (and yes they are the same thing in this case) in the very muscles which must be able to release and open during the birth process. Not a good recipe for easy birth, or smooth postpartum recovery.
Optimal Fetal position;
Left Occiput Anterior
Still not convinced? I’ll throw in one more consequence. During pregnancy the heaviest part of a developing baby’s body is their spine and the back of their head. We want the spine to finish pregnancy against the front of mom’s body as much as possible. This is because the best position for a baby to begin labor from would be not just head down, but head down with it’s nose facing towards mom’s bum, effectively creating a yin/yang space between the two of them. The movements needed for labor to proceed smoothly happen more easily if bay begins the process facing mom’s back. Facing forward can literally make the top of the head seem larger, and that makes for more challenging labors. Positioning the front of the pelvis to be the lowest spot, makes it so that gravity brings the heaviest point (the back of the head) to rest against the front of the pelvis. The result is baby’s body turns to face towards mom’s back. Conversely, chronically tucking the tail, promotes the baby settling to face forwards rather than backwards. Hello back pain, and a possible back labor. Not an ideal situation!
So what’s to be done? Well by this point you might be able to guess. STOP TUCKING!!! But of course it’s a little more nuanced than just that. We want to begin promoting finding a neutral pelvis. This means one which is not over tucked, or overly tilted. Neutral position for the pelvis isn’t actually when the top of the bowl (around our hip points) is level with the floor. This is what many of us are creating when we actively tuck our tail, or my favorite hidden tucking instruction of lifting the pubic bone towards the navel. In fact a neutral position for the pelvis involves the pubic bone moving towards the floor, and freeing the tailbone backwards to release the glutes. But the trick is being able to feel where this is. Here is where the pelvic floor becomes out best friend. Because the pelvic floor is the most responsive when in neutral, what we can focus on is how deeply we are able to feel our breathing. When in neutral, the pelvic floor expands downward on an inhalation and rebounds upwards on the exhalation.
Finding a neutral Tadasana:
Stand with the feet hip distance apart, the knees unlocked, and the second toe line of the feet parallel. Actively tuck the tailbone to feel the action. Then actively tilt the pelvic to feel the opposite action. Moving slowly from one to the other, pay attention to the sensation in the feet, and the depth of the abdominal breathing. For most people the sensation of neutral will be most evident when moving from tucked to tilted. As the groins deepen and the tail releases, there is an increased sense of weight in the feet, and a subtle but palpable engagement through the deep abdominals and pelvic floor. This is different from the navel drawing towards the spine. Many students describe it as an organization deep within their lower pelvis. Be sure the knees do not lock back as this will mask a pelvic tuck and reduce the awareness in the pelvic floor. When in neutral, many students report their legs feel much heavier and more solid. “Like tree trunks,” one student said. There is also a slight floating quality within the hip sockets, because a neutral pelvis is much more of a balance than a locked shape. It is as though we can internally feel the small dance constantly going on between our body and the field of gravity.
From this balanced position, we can now begin to build other standing postures and movements, but the key is to maintain the floating, spacious, and stable sensation as we turn, bend, and twist. In this way we help release the chronic tension building up in the lower back, hip flexors, and pelvic floor, and start promoting overall health and function throughout the body, before, during and after pregnancy.
Tadasana with neutral pelvis at 38 weeks of pregnancy
Key Takeaways (for those who skipped to the end)
Chronically tucking the pelvis leads to poor spinal alignment, less shock absorption, and a weakened pelvic floor
Many of us stand in a tucked position in our daily posture either from poor awareness or from old exercise instruction
In order to better balance the pelvis in line with the spinal curves, move the tailbone back and allow the pelvis to float on the tops of the femur bones
When in neutral, the pelvic floor is in its strongest position, which leads to overall better health and less pain
Standing with the pelvis untucked helps promote better fetal positioning for labor and birth