Sacroiliac Movement – Nutation And Counternutation

January 1, 2011     SI joint | back pain | nutation | Anatomy | Torso

Simplifying nutation and counternutation

Sacroiliac joint movement is often debated in the yoga world as well as the anatomy world. Many people equate what they feel is happening with what is actually happening anatomically at this complex joint. This is the beginning of a conversation here at


Read the comments below as there is a significant amount of information there!

As a preface, there was an original question asking if someone could explain what nutation and counternutation actually were. And, they asked how those movements relate to backbending type postures such as ustrasana, kapotasana, and urdhva dhanurasana.

As often happens in the blogosphere, people comment. And in an effort to help, they sometimes add to the confusion. A student of mine from the D.C. area asked me to weigh in and see if I could simplify and/or correct what others were saying about this topic. There was some confusion between pelvic movements and sacroiliac movements.

Learn a system for working with injuries

Sacroiliac movements versus pelvic movements

I’m hoping that I can bring a little bit of simplicity to this conversation.

Pelvic tilting

There are two movements that are getting mixed together here. First, there is pelvic tilting which is described as an anterior tilt and a posterior tilt. We define and discuss these from a neutral position, called anatomical position. That looks like someone standing upright, basically a tadasana pose.

An anterior tilt is when the pubic bone moves downward. Whenever this happens, we naturally make more of a lumbar curve, like a backbend. A posterior tilt is where the pubic bone rises or lifts. And, the opposite effect naturally happens in the lower back. We reduce the lumbar curve. These movements happen as the pelvis moves around the head of the femur.

Sacroiliac joint movements

Nutation and counternutation are movements that happen at the sacroiliac joint. The sacroiliac joint is where the sacrum meets the two sides of the pelvis. Nutation (from neutral again) is where the top part of the sacrum moves down and forward relative to the pelvis being fixed in place. Kapandji, referenced above, describes this as the sacral base moving forward and down. Counternutation is simply the opposite.

Everyone, unless their sacroiliac joint is fused, does some nutation and counternutation. The average person probably has, at most, somewhere between 3 and 5 millimeters of movement at their sacroiliac joint. In other words, not a whole lot. I’m surprised sometimes by how much emphasis is put on the idea of this movement happening in backbending type poses when such a small range of motion is possible at the sacroiliac joint.

How do these movements relate to backbends?

It is a good idea to consider all of the factors that go into a backbend and not get caught up in the part that moves the least. A good, or deep, backbend has much more to do with the hip flexors, such as quadriceps, adductors, and the iliopsoas, being open enough to allow the pelvis to move smoothly. When the muscles surrounding the pelvis allow it to move smoothly in backbending, it does not get jammed up in an anterior tilt and compress the lumbar region.

To clarify, since the question is regarding nutation and counter nutation, when you are in a deep backbend, your pelvis (relative to neutral) is in an anterior tilt. These forces will naturally put a force on the sacroiliac joint and if we look at the movement created there it would likely be counternutation. It is also possible for the sacrum to maintain its relationship with the pelvis. In that situation, if we took away all of the ligaments somehow, the forces on it would be counternutation.

Which movements can we physically create in a backbend?

This in no way speaks to what your intention is while in a backbending pose though. You might naturally try to undo some of the pelvic tilt, as people do when trying to tuck the tailbone under. This would be trying to tip the pelvis more into a posterior tilt from an already extremely anteriorly tilted position. So it’s not going to put the pelvis into a posteriorly tilted position because you’re not starting from neutral. If you do this, it would undo some of the counternutation and potentially allow the sacrum to nutate slightly.

People who are naturally flexible will have more movement at their sacroiliac joint. They may actually feel this, or control this movement better than the average person. I certainly can’t argue with anyone’s experience.

I also wouldn’t suggest that a student try to do this movement specifically. It will either happen or not happen on its own. However, if someone is dealing with sacroiliac dysfunction or pain, then pay more attention to how much or little of this movement is happening.

Signup for our newsletter!

Get the latest articles in your inbox each month.

"*" indicates required fields


As you can tell, the sacroiliac joint and its movements are complicated. I hope I’ve simplified this or at least, broken it down so you can distinguish between pelvic movements and sacroiliac movements. I go into more detail about the sacroiliac joint and movements of the sacroiliac joint on pages 143-145 (1st ed.) of my book Functional Anatomy of Yoga.


  1. Pingback: Piriformis – A real pain in the … – Freedom Arts & Bodywork

  2. David-

    How do you get the pelvis to be neutral again from an anterior tilt? Picked up a case of water with my back, and ever since have had issues with my SI joint.

    What muscles need to be released/lengthened and are there trigger points that can help the pelvis become neutral again?

    How would you keep the pelvis from tilting again?


  3. Christine Kent at Whole Woman yoga has done a lot of research on nutation and counter-nutation of the spine. Their findings are:
    In nutation the inspiration pulls the lumbar spine forward a little thereby incresing the lower lumbar spine. Nutation causes the pelvic wall to lengthen from pubic bone to coccyx and to tighten across the ischial spines. Nutation also causes the deep perineal muslces to tighten. These forces are involved with pelvic organ support and stabilisation.
    In counter nutation, the lumbar curve flattens, the pelvic diaphragm between pubic bones and tailbone shortens and slackens s the tension on theischial spine is released. Counternutation slackens tension in the muscles surrounding and supporting the urethra and vagina.
    In good posture the pelvis is most stable when in nutation.
    The pelvis moves alternately from nutation and counternutation. The weight bearing side is nutated, while the the other side is loosened for the flexibility necessary to swinh the opposite leg forward.

  4. Pingback: Sacroiliac Blues « DippingBird « DippingBird

  5. I fear people may be misled when you say:
    “when one is in a deep backbend, your pelvis (relative to neutral) is in an anterior tilt.”

    This depends on our frame of reference.

    If we look in terms of earth and gravity, then yes. But, like you said, the hip flexors are greatly stretched in advanced backbends.

    For most normal people who have anterior pelvic tilt, it is actually because their hip flexors are tight.

    Relative to the legs: the pelvis isn’t tilting forward at all. Rather than hip flexion, we actually get hyper extension.

    What I think creates the pelvic tilt is that the legs tilt forward, and the pelvis shifts forward on top of it, and follow the tilt of this legs.

    This is to keep balance, as the upper body is bending back behind the center of balance.

    This is like the opposite of how when we do a forward bend, our legs tilt backward. In this case, the pelvis shifts backward, but it tends to tilt forward.

    1. Post

      Thanks for adding to this conversation.

      I fear that you’re mixing movements. This is a particularly difficult topic about nutation and counter nutation.

      So all of the movements that are involved are
      pelvic tilting
      hip flexion/extension
      and SPINAL movement

      That’s a lot to keep track of and we need a frame of reference to look at them all. Since this is an Anatomy and Yoga website, the frame of reference is anatomical position.

      I’m not clear on what frame of reference you’re wanting to use… just the hip joint?

      You’re right when you say that the pelvis isn’t tilting forward. It is in an anteriorly tilted position… because of the spine… and it is also true that the hip joint is in hyperextension… but because of the position of the spine and the tension that you mention in the hip flexors, the pelvis is actually being pulled in an anterior tilt while in it’s backbending position.

      In anatomical terms I honestly am not clear about what you mean when you say our legs tilt forward or backward… Sorry I’ve never heard this before and amd not sure I understand it in the context of what you are saying here.

      Perhaps you can clarify a bit more?

  6. I don’t see how the pelvic floor muscles would be working against the sacrotubinous ligaments. Both reach forwards from the sacrum/tailbone.
    What else is there that can act to pull the bottom of the sacrum/tailbone forwards? The piriformis probably helps but then you’d need to have the thighs stable.
    Then the question might also be, if the ligaments that bind the sacrum to the pelvis are so strong, what would cause nutation and counter nutation? Widening the sitting bones and narrowing the top of the pelvis, or the opposite, narrowing the sitting bones and widening the top of the pelvis?

    1. Post

      All the ligaments that surround the SI joint, of which the largest and most obvious is the sacrotuberus ligament stabilize the joint. Their tension maintains the integrity of it. So… the pelvic floor muscles… when contracting would have to have enough strength to work against the tensional resistance of the ligament. It’s true that it’s not like the ligament is working in an opposite direction to the pelvic floor. It’s neutral and maintains tension and stability.
      Having said that, I may have to revise an early statement. I still don’t think that the pelvic floor has enough strength by itself to move the SI joint. I would say that the pelvic floor does have an effect on it as does the piriformis which you mentioned. which leads to your question… what does?
      I usually describe and have understood the SI joint to be a more passive joint. It moves as a result of other movements, particularly the end of range of motion of the surrounding joints such as the hip joint and the lumbar spine. So it is most commonly the weight and force created by movement that moves the SI joint.
      I would tend to think that if we were trying to move the SI joint it would be a combination of muscular contraction and movement and or positioning. Positioning being something like a standing forward bend… does slightly widen your sit bones. Movement… walking definitely creates forces through the SI joint that have it move.
      But the average amount of movement is about 3mm. If you have a particular moveable one, then it’s more realistic that your pelvic floor have MORE impact on the movement of the SI joint when not moving but just standing still or perhaps sitting.
      All of this is theory anyway… no one is inside the joint while these things are being performed and measuring the movement at the SI joint is very difficult under highly scientific conditions.
      The feeling that it creates whether literal or just intentional is most important. It’s always difficult to marry the hard science with the intention… especially in subtle movements. Its hard to prove either way… so I stick with engaging my pelvic floor and working with the qualities it creates.

  7. Personally I think that the movement where the tailbone moves towards the pubic bone (counter nutation?) can be caused by mula bandha or if you prefer a tightening of the musculature just behind the pubic bone.
    Moving the opposite direction may (or may not) be controlled by the erector spinae.
    I think the action easiest to create deliberately is that of pulling the tailbone towards the pubic bone. (in an upright pose, this “resists” the downward push of the spine on the sacrum.)
    Practice gently pulling the tailbone forwards (towards the pubic bone) and then releasing and repeating, you can learn to feel the tail bone moving forwards (a tiny amount) and then releasing.
    If you can do this action at will (and feel it) then you can try to use this same action in a back bend. Feels good, then continue to do it. Feels not so good, then don’t do it.

    I think ultimately the better we get at feeling the body and controlling it (and in this case controlling the relationship between sacrum and pelvis) the less this conversation matters because we can feel for ourselves whether we need the action or not.
    (and if you can’t control nutation or counter nutation then it’ doesn’t matter anyway.)

    1. Post

      I do think it’s a good intention Neil. However I have to be a bit of a downer in my thinking. Pelvic floor muscles vs. sacrotuberus ligament? Both posterior and anterior? As well as the iliolumbars and the general density of the ligaments that hold together the SI joint. I’m not convinced that these muscles have the strength to make the SI joint move. They are in essence on the thinner side, not particularly powerful.
      A good intention, sure, why not. I think the space you’re referring to may be coming from a movement of the pelvis that lengthens the lumbars.
      The truth is whatever works… use it!
      Thanks for commenting,

  8. Hello to all I even have some doubts about the nutation and comnutacion, can help with a definition a little me but simple, I am student of first semester and this work is very important Thanks

  9. Pingback: Piriformis - A real pain in the ... | Yoganatomy

  10. Pingback: Piriformis - A real pain in the ... | Blog

  11. Hi again!! Hey –check this out –

    I think part of the problem might be in the terminology? When we take the spine into flexion (increasing the primary curves of the spine), the sacrum counter-nutates in relationship to the S-I joints or extends (relative to the lumbar spine) –and opposite for extension, increasing the secondary curves, counter-nutating at the S-I joints, sacral “flexion”.

    For sure we have choices, but this moving image does a good job of showing what occurs naturally! From there we can do any number of things to deepen a forward bend or back bend, choosing either nutation or counter-nutation… as Coulter argues. I think this is what Judith is talking about when she describes the natural sacral rhythm.

    Thanks again!! 🙂

  12. Hello again! Thank you again for such obviously well-thought-out conversation!! I think that maybe the original scenario might be where we fall apart, which as you said, is just fine! I don’t really place too much weight on the experiment Judith has us do (excuse the slight pun!), but i think that it is useful to feel the sacral movement. I think that Patty and I would both agree that as the weight of the spine falls forward of the center of gravity of the skeleton (which is right at S2 i believe… Gorman’s Body Moveable) if the pelvis is fixed, which is an artificial scenario, but let’s go there for now, that the natural movement at the S-I joints would be nutation, not counter-nutation; but we can’t really remove all the ligaments and muscles that support and stabilize the pelvis, so I’m not sure it applies. The tensile strength of the ligaments are going to connect the joints, and I think to a degree, prevent what would in a vacuum be nutation as the weight of the spine falls forward of the skeletal center of gravity, so i think that may be our problem. We can tether the tail to the earth, which would then allow counter-nutation, not fragmenting the spinal energy at all… but we can’t really think of the pelvis as completely immobile, because as soon as counter-nutation or nutation occurs, there is a corresponding movement in the pelvic halves. The sit bones move away from one another and the ilia towards one another as the sacrum nods forward, the reverse for counter-nutation. So, it would follow that if we anchor the sit bones towards the fronts of the feet as we move into flexion, pulsing them towards each other, then counter-nutation would occur in a forward bend. Opposite for back-bend, also tethering the sit bones to the fronts of the feet, but allowing the sit bones to softly part, ilia moving towards one another, allowing nutation.

    So, I think that it can be done both ways really –and i guess it might depend on the person. I do know that with the many people I’ve worked with therapeutically, when I’ve given them that scenario, their pain decreases. I will say that especially with hyper-mobile, hyper-flexible people, women primarily, allowing the sacrum to nutate in a back bend, (while stabilizing the sit bones towards the fronts of the feet in urdva danurasana for example), they are able to modulate the forces at the L-S and T-L junctions effectively using breath, bandhas, and skeletal stabilization principles (Bonnie Bainbridge-Cohen) including the thrust/counter-thrust principle that states that to have smooth articulated movement through the bones when one bone is moving around another, you apply a counter-thrust or force in the direction of the non-moving bone….

    Coulter does adress urdva danurasana, and says that it requires sacral nutation… as for dropping back, it is possible to do in such a way that you don’t have to push your hips forward. If you root the tail and connect the ischial tuberosities energetically towards the fronts of the feet via the calcanei, then you can lower into urdva danurasana allowing the sacrum to nutate.

    I appreciate that there are many different ways to move and to stabilize, and am beginning to think that if it’s this diametrically oppositional, then it must indeed be yoga!! One of my teachers always said if there’s no paradox, there’s no yoga… 🙂

    Thank you SO much for the wonderful conversation back and forth. I admire your perspective and appreciate the dialog!!

  13. Well Hello Again!

    I think this is a great conversation to be having in this way, meaning out in the open, as a means for all of us to inquire, question, and investigate. I feel the need to say this because I’m very aware of my own nature. I tend to question, what’s been said, what’s been written and I smile when someone starts questioning the rules. Both yoga and anatomy are broad subjects with many points of view and perspectives… There is so much variation in anatomy and in how that anatomy turns into shapes on a yoga mat. I think we can all agree on that.

    I do tend to be a bit of a debater and a contrarian, so I acknowledge that, and it seems that we may end up, if not already, on two different sides or two different perspectives of this particular piece of the puzzle. As we do, or if we do, I just want to say in the beginning that none of my desire to contradict anyone is personal, it’s just the way I see it and I might be wrong in the end. So it is with gratitude that we get to have this elevated conversation amongst us who know enough anatomy to talk about it at this level. Thank you for that.

    I feel like I have to see if there is a common place of agreement fundamentally. It seems that there are definitely pieces of that already in various places so I may end up re-iterating them in this next part.

    We seem to agree that nutation is the top of the sacrum tilting or rotating forward and down toward the pubic bone relative to a pelvis that isn’t moving and that counternutation is the top of the sacrum tilting and rotating backward away from the pubic bone relative to a pelvis that isn’t moving.

    We also seem to agree that these movements are passive and a result of forces acting on the SI joint. What then are these forces? I would say, weight, gravity, tension of the soft-tissues including but not limited to muscles. Perhaps we might also agree that the forces created by pelvic and spinal movements when combined in certain ways will put force on the SI joint. In my own workshop I often talk about the hip joint, the SI joint and the lumbar spine as another example of a kinematic chain and an interlinking of function happening between them.

    The same movement could also be caused by the sacrum being stabilized and the pelvis moving at the SI joint. In this case an anterior tilt of the pelvis relative to a sacrum that does not move would be called counternutation. The opposite is true where a posterior tilt of the pelvis relative to a sacrum that isn’t moving would be called nutation at the SI joint.

    Do we agree on the above?

    So Let me take this idea of passive movement a step further. Let’s say We have a pelvis with a spine sticking up from it, no arms, no legs, but we’ll include a rib cage and skull. A skeleton of these parts, just to keep it clean and simple. Let’s say we turn it sideways and we’re looking at from the side and we see the beautiful curves of the spine in the lumbar and thoracic etc… Let’s now say that we put the entire structure, pelvis and spine on the floor so that it seems like it is all growing out of the ground… in other words the spine is upright and perpendicular to the ground, not laying on it. Let’s now say that the floor magically grabs the pelvis and it cannot move. The two side of the pelvis are completely stuck and immobile.

    I think we’d all agree that there is a gravitational line running through the spine. When it passes through the pelvis where would it be? I’m not sure exactly but probably pretty close to the same plane or line that the SI joints are in, no?

    So, playing with the passiveness of the joint, and the forces such as weight and gravity… remember the pelvis is locked in place in this scenario… If the majority of the spine moves in front of the imaginary gravitation line that I suggested above, what movement or force would be placed on the SI joint? Let’s say all the ligaments surrounding the SI joint were also gone in this scenario, what would happen at the SI joint if the weight of the spine moved in front of the pelvis? If there were no ligaments to hold it up anymore, would the spine fall to the floor in front of the pelvis? Would this falling not happen at the SI joint? And then what movement would be required at the SI joint for the spine to fall forward? The only answer I can come up with is nutation… although an extreme example of it that would never happen. Point being that the weight and force of gravity would cause nutation to happen if the spine were in front of the gravity line I mentioned.

    In the same scenario, if the majority of the spine moved behind that line of gravity what would happen at the SI joint with a fixed pelvis? For whatever reason, I can only imagine the exact opposite of what happened above. That is the force of counternutation happening at the SI joint.

    I don’t mean to oversimplify the whole of this conversation. I realize that we are moveable and I also realize that this is the simplifying the movements at the SI joint but it is also fundamental for the onversation. If we don’t agree about the above scenario we’re not going to agree on anything that evolves out of it… Which is OK.

    If I take this to the next step of a yoga forward bend or back bend… In a forward bend, at some point as I move at my hip joints my pelvis gets stuck, it stops rotating around the heads of my femurs. Why? because the hamstrings and perhaps some other tissues don’t allow it to anymore. Their tension as it attaches to my sit bones is holding my pelvis in place. The only reason the tension is there is because of the weight of my upper body and gravity bringing by body to my legs at the hip joint first and spine second. At that point my spine is well in front of my pelvis, my arms acting as even longer levers, my lower spine may round in flexion.

    The force of the hamstrings and we see this with students with tight hamstrings is that they make the pelvis to a posterior tilt (relative to the spine above it) and force the low back to round. If the pelvis is moving back ward and the spine is completely in front of it isn’t it the same as my little simple scenario except more extreme in a way? I cannot see how this forward bend would or could create counternutation at the SI joint.

    The opposite for a backbend. The pelvis in the air, If we could draw a line horizontally through the pelvis, SI joint and spine, would we not find that the majority of the spine, arms and head are way behind this line? And the primary force acting on the pelvis are the hip flexors that are being stretched… and they are… being stretched as the hamstrings were in the forward bend. Their natural force is to pull the pelvis in the direction of an anterior tilt… this happening while the spine is completely behind it. To me, in my mind, taking it back to the basic scenario… the more complicated one creates counternutation, doesn’t it? I cannot se how this creates nutation at the SI joint.

    Having said all of that. I am not even going to argue for or against allowing or making this movement happen at the SI joint. Simple enough for me to say, if that movement is there, it’s probably there for a reason.

    Unfortunately Judith isn’t here to further explain what she means in her book. I have to say that the test of putting your hand on your sacrum doesn’t cut the scientific mustard for me…. sorry lot’s of things could be moving and you’re only feeling your sacrum.

    I’d rather not go any further, because if we’re in disagreement about the basic movement and the forces that create it… We’ll only continuing going around in circles about what’s happening in more complicated movements and we can agree to disagree.

    In terms of how to move and how to teach people, I couldn’t agree more that we should be creating the correct patterns from the beginning and avoid having to undo things later if possible. I’m all for making and keeping a back bend a backbend. I’m also all for balancing out the tissues of the body especially around the SI joint including psoas, piriformis, pelvic floor, and abdominals… These are crucial to so many things including basic movements and support.

    With that, I leave you for the moment and look forward to hearing what comes up next.

  14. Thanks guys!! This is so very interesting –Judith states “It is important to understand the relationship of the movements of the lumbar spin and the sacrum. When you perform a back bend –perform active spinal extension –your sacrum passively nutates, and S1 moves anteriorly. When you forward bend –perform active spinal flexion– your sacrum passively counternutates, and S1 moves posteriorly. Nutation and counternutation are passive movements only but they must accompany extension and flexion, respectively, for them to be normal, healthy, and complete. These movements of extension with nutation and flexion with counternutation are called the lumbo-sacral rhythym”… she then goes on to give an example of placing your hand over your sacrum as you slowly sit down to feel how the sacrum counter-nutates, and how it can move back to neutral if you sit with the spine long and lifted, in neutral spinal curves –then she has us feel for what happens upon standing, and the sacrum nutates as you stand back up.

    I think that in Kapandji’s book it’s confusing because 1) he’s talking about what happens when you’re lying down on the floor –which would catch the pelvis and sacrum on the floor –so when extending the leg, because the movement is limited by the weight of the pelvis on the earth –it could cause the sacrum to counter-nutate –but this isn’t the natural movement –it is caused by the orientation of the pelvis and the possibility of catching the sacrum on the floor relative to it. Again –i think the problem is that we’re not taking into account the options available in easeful, unsegmented movement of the spine. If the pelvis is stabilized, then the movement will happen in the sacrum, and that natural movement is as Judith and David state. In terms of urdva danurasana –I think it still applies. You ground the pelvis and allow the sacrum to nutate –AND support from the front, to brake the action so that the forces don’t jam into the L-S junction.

    Kapandji does bring up a good point in his discussion: that based on the 3 different theories of nutation, (which posit the different possibilities of movement and that the movement happens in different places) –thus it may well be that different types of movement happen for different individuals. I could see how in someone with a lax pelvic floor and low abdominal muscle tone, and consequently a hyper-lordotic curve, it might be tempting to tell them to tuck their tail in a back bend –but I think if we look at creating abdominal support, pelvic floor tone, and bandhas, that individual could relieve some of their back pain and hyper-lordosis without fragmenting the movement in the spine, by simply stabilizing the movement of the pelvis and releasing the tail, as opposed to tucking it. I may be cutting hairs here, but it seems to have made a huge difference with people i’ve worked with therapeutically who present this way. Coulter does agree that nutation should occur in urdva danurasana –but he also advises beginners to counter-nutate –again for “safety” reasons, and I think this is a mistake –mostly because if that beginner continues to perform that fragmented movement in the spine over time, and develops more pelvic tone and abdominal support, then he will eventually have to undo that which has been over-done. I think we should treat beginners as more able than we sometimes do… they’re surprisingly able to differentiate pelvis from spine if we spend some time with them, teaching them how… but that’s hard to do in a big class, so i totally understand why people have taught the “tuck the tail” thing –it’s a very rudimentary way of keeping that student “safe” in a backbend, but I believe it fragments our experience.

    If we look at the student with a tight pelvic floor, and tight psoas, with no lordotic curve –to have that person tuck their tail in a backbend is not at all helpful for them. They need to develop more movement and freedom in the pelvic floor, hip flexors, and low back. They really need to learn how to allow that tiny bit of movement in the spine at the SI joints to enjoy more freedom in the entire spine!

    I do agree that the tucking the tailbone idea makes people posteriorly rotate the pelvis –because they’re not differentiating spine from pelvis –and it IS a very small movement for sure, but I question the advisability of having people reduce the flexion or extension in the lumbar spine –that’s the part of the spine designed to do that –I see way too many “experienced” yoga people with flattened thoracic curves from over-backbending there… not such a problem with beginners, but again, if we take them that route –eventually we’ll have to undo that which we’ve done to create balance. Why not take them along the path that will bring them to a place where they’re not relying on their connective tissue to determine their range and position in space to begin with? Then we don’t have to go back and undo….

    Thank you so much for the continuing interesting input and conversation! One of my teachers used to say –“if there’s no paradox, it’s not yoga” –which certainly seems to be true here!!

  15. So the weekend is over and I’ve given more thought to the nutation counter nutation in a “relaxed” backbend. I’m still not even sure of what exactly is meant by that but I was writing a piece about the psoas and its relationship to the SI joint and had a thought and connection to what I wrote in the last post on this subject.

    Here it is. If by relaxed backbend, we’re saying that the pelvis doesn’t move in its positioning in space but we do allow the lumbar spine to go into more than normal extension, I want to use the word collapsed, and realize perhaps this is what Coulter is referring to when he says relaxed backbend… then, yes, I can imagine and see the forces of this creating nutation at the SI joint.

    I want to then say that I don’t think this is true if you’re standing and pushing your hips forward at all to counter balance your weight in say… dropping back into a backbend from standing, in this case… I stick with the force of counter nutation being present on the SI joint.

    What do you think?

    Regarding the general discussion of fluidity of the spine, I do agree with what both of you have said, although my wording would be different, that’s all. I will sometimes say to students to find the undulations of the spine through your movements… even exaggerate it a few times to “unlock” it a bit. You both seemed to refer to this in different ways.

    Thanks for continuing the dialogue,

  16. Well thank you both for continuing the conversation.

    A couple of quick comments from me is all you’ll get on a Saturday morning.

    Karen quotes David Coulter and Judith Lasater about the actual movement during back bending. I don’t have Judith’s book but did look to see what Coulter said (again). Coulter is talking about relaxed standing back bend and the image he shows is someone adding a bit of lumbar extension. I don’t think this speaks to what actually happens in a full fledged backbend… which he never addresses!

    he also references Kapandji, whom I’ve referred to for years as quite a good investigator in the 70’s. Kapandji states that in a relaxed reclining supine position the tension of the hip flexors will pull the pelvis into an anterior tilt placing a force on the SI joint of counter nutation. It’s easy for me to imagine this, I’m really not sure what Coulter is referring to in his section but I have to disagree with him.

    Does Lasater comment about a full back bend or is she just playing off of what Coulter has written in a relaxed standing back bend which is really a slight extension of the spine… it’s all very non-specific at that point in Coulter’s book if you ask me.. and the lack of acknowledging what would happen in a full wheel doesn’t help unfotrunately.

    As for tucking the tailbone… this makes people posteriorly rotate the pelvis not specifically move their SI joint or their tailbone. It’s an intention as opposed to an anatomical movement, but if the sacrum stayed in place and the pelvis rotated in this direction, you would actually neutralize or at least head in the direction of neutralizing the SI joint. In my experience, going from a counter nutated position to a more nutated position. Personally I think the effect is more about reducing the extremity of the lumbar spine extension in this position as well as putting pressure on the hip flexors that are normally causing the compression in the lower back.

    OK… that’s me for the weekend. Thanks for keeping the conversation alive and the dialogue.

    Remember, we’re talking about a few millimeters of movement in the average person.


  17. Hi again,
    I certainly agree with Karen on all of the above comments. I agree that the term “tuck the tailbone” in back bending is such a sacred cow in yoga that many of us – as serious practitioners over a very long time – have not even considered that it might be a detrimental action! We heard this instruction over and over from all the senior teachers for many years. We were instructed to “move the back bending action into the thoracic spine” and “to not allow the lumbar to extend too far in back bends”. It is really like the emperor has no clothes and we are experiencing this in our bodies and mistrusting our own experience because everyone seems to agree with this principle. UNTIL, David Coulter and Judith Lasater broke open the subject! The fact is that for most people, not just many, tucking the tail in a back bend interrupts the flow of energy in the spine. In the words of my teacher, Bonnie Bainbridge Cohen, “If you want to bend backwards, then bend backwards!” In a back bending posture if you tuck the tail you effectively lock the sacrum in counter nutation which is the opposite of what you want to do.

    Now, there is the argument that there will be no support for the lumbar spine and that it will collapse into excessive lordosis and become compressed. OF COURSE, it will, IF you do not elongate the spine appropriately – from both head AND tail ends – AND support the lumbar spine from the FRONT. Front support of the spine comes from many different body tissues. Again, another way we misinterpret the body in our yoga practice is by thinking of all supports coming from the musculoskeletal system! This is a big problem. The supports along the front of the spine are organic, developmental, and glandular to name a few! They provide very ample front support of a spine that is fully extending from head to tail in a back bend without interruption of the flow of prana from head to tail!
    Thanks again for talking.

  18. Thanks to all of you for the ongoing important conversation, and just to be clear: many different sources: Judith Lasater, H. David Coulter, and others state that in relaxed back bending, the sacrum naturally nutates. When looking at the picture of the sacro-iliac joints above –the base (or widest) part of the sacrum is going to move anteriorly and the coccyx posteriorly and the ischial tuberosities will widen slightly to accomodate that movement. It is in passive flexion of the spine that the ischial tuberosities move towards each other slightly, allowing the sacrum to counter-nutate. Even though the spine and pelvic halves are separate entities, so-to-speak, they can and do move in close relationship to one another precisely because of the small degree of possible movement at the S-I joints. The bony structure, in addition to the organs, psoas, and diaphragm, support and brake the action of nutation or counter-nutation. It is not necessary to perform the opposite movement at the S-I joints (ie counter-nutation in back-bending, nutation in forward bending) to stabilize the lumbar spine and prevent too much force at the lumbo-sacral joint. That can be accomplished by maintaining support at the pelvic floor –hovering it over the earth, and using breath support, mula and uddiyana bandhas, whatever soft-tissue support you choose to access. I agree with Patty’s emphasis that we need not instruct people to fragment or harden the spine by bringing the low spine into flexion using counter-nutation in order to stabilize the sacrum when bringing them into a backbend. What we need to do instead (in addition to instructing them how to use the soft tissues and breath to provide support) is have them root the tail and stabilize the ischial tuberosities, so that the spine can move in an unsegmented fashion, coming into extension throughout the entire spine. In the picture above, nutation would take the top part of the sacrum away from the viewer (as it is a posterior view of the pelvis) and the coccyx would be coming towards the viewer, in natural extension of the spine. The sacral base (the upper portion) in the above view would then move towards the viewer and the coccyx away in counter-nutation, or flexion of the spine. I believe that some of the confusion lies in the terminology. Nutation occurs in natural/relaxed spinal extension, but it is called sacral flexion, and counter-nutation occurs in natural/relaxed spinal flexion, but is called sacral extension. Also, some of the confusion comes from the movement that happens in the pelvis relative to the SI joints. When the sacrum nutates, the pelvis, relative to the SI joints can tilt posteriorly, and the opposite for counter-nutation; however, it doesn’t follow that if you anteriorly tilt the pelvis, the sacrum automatically counter-nutates –there are options there –because the sacrum is part of the spine and not part of the pelvis. This is one of Yoga’s sacred cows… tucking the tail in backbending –and i’m so glad we’re picking it apart to understand it! And i think that just because there is little movement there (or maybe precisely because there IS so little movement there!) doesn’t mean that it’s not a very important part of the spinal movement process… it certainly causes enough people pain! We need to make sure our students are integrating themselves in their experience. Fragmentation is the problem –on and off the mat!! Great discussion topic!! Thank you!!

  19. Hi David,
    Just found this blog and I’m enjoying reading it. I’ve had pain on my right hip for the longest time and I came to the conclusion after a long time of not getting better that it is Arthritis, until I got x rays and there’s no such thing on my hip, therefore the doctor says that it must be some sort of tendon inflammation. I wonder if it has anything to do with the si joint as I recall you saying one day that this kind of injury happens more on flexible people.

    1. Hi Marisa,
      Funny that you found the blog in a somewhat random way. There does seem to be something to those that are generally more flexible having more mobility at this joint as well as all others. It would usually be the extremes of movement through the hip, pelvis, spine relationship that would aggravate it. This would include deep twists, forwardbends (including leg behind head) and backbending. See if you notice the inflammation or irritation increase after working these types of postures.
      It’s also possible that you have triggerpoints referring into the area… some of the most common that can strongly refer right to the PSIS is the quadratus lumborum… especially the deep portions. Here’s a link to that image and the image itself. We have spoken enough about yours specifically so I’m just throwing out some possibilities. Call me if you’d like to talk about it or explore it.
      QL Trigger Point

  20. Thanks David – this was super helpful and timely for me.
    Meant to make your last Philly workshop but alas, was in crisis mode due to what the naturopath and chiro said was a dislocated SI joint.
    Ouch. Took a few weeks off practice and then started up at “half mast”, avoiding deep forward bends and craving backbends. Almost back to normal now!
    It was fascinating to hear the orthopedist at Penn say that this wasn’t possible because the SI wasn’t a mobile joint,
    and when I asked about nutation/counternutation he claimed never to have heard of it. Hah! AND he was Indian!
    Anyway, I’m hoping to see you when you’re here in March – and would love to see then what you might advise about protecting myself
    from this kind of injury in the future.

    1. Thank you both for your posts. Jackie, very interesting that an orthopod has never herd of nutation! Being fair though, dislocation in the way we think about dislocating a shoulder is not quite what the Chiro and Naturo mean either… Something seems to be putting pressure on it, that much seems obvious.
      I hope to see you in March.

  21. Hello All,
    I am so very happy to see this conversation. I completely agree about there being a lot of confusion about tying the nutation and counter-nutation in with the tilt of the pelvis. Obviously, they are in fact two very different actions that are both important to understand. Let’s just take tadasana to start. Both sacral nutation and pelvic tilt should be neutral. We can all agree with that. I believe that way too many people are “tucking” their spines – counter nutating their sacrums – in the effort to elongate the lumbar spine even in tadasana. In many cases the best action will be to actually remove the anterior tilt from the pelvis AND, interestingly, take the entire pelvic floor back, essentially “hovering the pelvic floor” in an anterior direction. In most cases this will remove the excessive lumbar curve WITHOUT hardening the spine!

    We need to separate our perception of spine from pelvic halves in the pelvis. Spine is core and if any action hardens the spine it is a detrimental action. I believe that so many long time yoga practitioners are hardening their spines in back bending and that they have been doing it for so long that they don’t even feel it as a hardening. They just think they have “stiffness” in the lower back, perhaps.

    I have found that even with beginners and when backbends are not particularly deep there is a need to allow FULLY the nutation as one of the initiating actions in even a small back bend. Front body, especially organ, psoas major, and the diaphragm stem provide the support that is needed to keep the lumbar from collapsing.

    I think it is a mistake to think that beginners cannot bring in these levels of support. In my experience once they know about them they are able to bring them in quite well.

    Interrupting the flow of the spine into extension when we are entering an extension posture fragments the energy flow along the spine. Fragmentation is another thing that we are so accustomed to that we often don’t even know it is going on.

    These are my thoughts for now. Again, thank you for opening this dialogue!