We recently received an inquiry about positioning the pelvis in yoga poses that I thought it worth addressing in a general, full-length post. Let’s start with the question:
Dear YFHA Staff,
The phrases "Tuck in and Tuck out" are very commonly used by several of my teachers. I get so confused listening to those words that these days the minute I hear anything close to "Tuck" my meditative yoga practice goes for a ride. What are the teachers referring to when they use those words? Are they alluding to the movement of sacrum? For eg: in Bridge pose and other supine poses, do you draw the sacrum in (I guess the word is Tuck in) or do you draw it out? Can't we just keep the sacrum in neutral position and still get the benefits of the supine poses?
Yes, dear reader, there is a lot of talk about “tucking” the pelvis these days in the yoga world! Although I don’t hear or use the same exact phraseology as you teachers are using, I think I have a sense of what they are going for. I might suggest the terms “tipping” and “tucking” of the pelvis, as a whole, for what is being suggested. In anatomical terms, the action can take place relative to the top of the upper leg bone, the femur bone.
When you “tip” the pelvis, this means you are rolling it forward and down over the head of the femur, in what is referred to in anatomical circles as anteversion or flexion at the hip joint. This happens to some extent in forward bending poses, like Uttanasana (Standing Forward Bend), when we roll the hips forward and down to initiate the forward bend.This movement also encourages the forward rounding of the lumbar vertebrae due to the effect of gravity, known as flexion of the lumbar spine, in the specific situation of Uttanasana. Yet we are also sometimes encouraged to extend the lower spine, as in a backbend, when entering into some forward bends. In other words, as the pelvis is rolling forward over the thighbones, we simultaneously extend the rest of the spine as in a backbend. This can be a useful suggestion in some lower back injury situations, or if you are focusing on strengthening the extensors of the back body. But it could be just as helpful in some cases, to allow the natural flexion of the lower back in Uttanasana accompany the anteversion of the pelvis.
Tipping the Pelvis (Uttanasana)
The other action, which I call “tucking” of the pelvis, is essentially the opposite action, in which the pelvis rolls backwards over the head of the femur bone. Anatomically, this is called retroversion or extension of the pelvis. It is an essential action, at least to some extent, when we are trying to do some of our back bending poses, like Dhanurasana (Bow pose) or Urdhva Dhanurasana (Upward Bow pose), which require some length and opening at the front of the hip joint to successfully achieve these more advanced backbends. Just like with tipping, the spine may have a natural inclination that accompanies tucking, like some extension of the spine if we are trying to do Upward Bow or Wheel pose. However, if you observe someone standing in Mountain pose, and ask them to exaggerate the tuck, you will notice that the lower spine rounds back, which actually means the vertebrae are tipping forward into flexion. If you then ask the person to tip the pelvis forward, you will see that the lower spine goes into a backbend shape, bowing forward towards the navel. This indicates that the lower spine is going into some extension.
Tucking the Pelvis (Backbend)
Playing with this movement of the pelvis in Mountain pose is a good way to begin to feel these actions and the results at both the hip joint and the lower spine. You might also start to sense if one way feels more typical of how you hold your pelvis relative to you upper leg bones when standing. If your teacher was suggesting that more tip or tuck would be better for you, see if his or her suggestion actually does what predicted. Be a little skeptical, especially if you are working with a newer teacher. There is a lot of subtlety to this pelvic alignment, and it first it will likely feel a bit strange, even if it ultimately might lead to better posture and lower back alignment. When looking at supine poses, done lying on your back, face up, you will want to do the same experimenting to see what works best for you.And I have not even mentioned the movements that can happen between the pelvis and the sacrum, known as nutation and counternutation! Shari and I have written some about that elsewhere, so take a re-read of some of those posts (Friday Q&A: Trikonasana, Janu Sirsasana and the Sacrum and Yoga and the Sacrum if you are not familiar with these terms. Judith Lasater, in her book Yoga Body, has a discussion of what happens in regards to these two actions in forward and back bending poses. There is some controversy about how much nutation and counternutation actually take place in adults in yoga poses, but there is a lot of variability in how much “intra-pelvic” movement (between just the two pelvis bones and the sacrum bone) between individuals from my observations. It is always wise to get the opinion of an experienced teacher who can watch your body move in different poses to see where your fall in this regard.
I would also suggest that you directly ask your teacher to stop and demonstrate the actions of tucking so you can get a clearer idea of what he or she is talking about. Sometimes I find that without that clarity, I am just guessing as to what the teacher wants me to experience. And it would also be reasonable to ask why he or she feels this is important to experience. So, ask the how and the why when these sorts of instructions are creating more confusion than clarity, and rock that pelvis on.
