Note: Touch or hover your mouse over underlined terms for a definition.
The pelvis has three primary skeletal components: the right hip, the left hip, and the sacrum. While these pieces can move independently, they often work together as a unit, and the each piece exerts an influence on the pelvis as a whole. They will be discussed collectively in this article. Pelvic tilt involves a simultaneous movement of both hips, the sacrum, and the lumbar vertebrae.
To understand pelvic tilt, find your ASIS – a small bony projection at the upper front of the hip bones. When this point moves forward and down, the pelvis is in a state of anterior tilt. When the ASIS moves up and back, towards the spine, this is posterior tilt.
This movement of the pelvis is important to be aware of in most Yoga positions as it has a significant effect throughout the body. Keep in mind that the pelvis has other axes of movement as well, and they all influence each other. I do not mean to imply that tilt is always the most important, but it’s too complicated to tackle them all in one article.
When the pelvis is tilting anteriorly, the hamstrings and abdominals are lengthening, the lumbar spine is in extension (arching forward), the quadriceps and muscles of the back and spine shorten.
Conversely, a posterior tilt shortens the hamstrings and abdominals, lengthening the muscles of the back and the quadriceps while the sacrum moves downwards (e.g., ‘tucking the tailbone’) and pulls the lower back with it. (unless you’re very flexible or move the rib cage forward, the lower back will most likely be in a more or less neutral curve.)
A chronic tilt in either direction is a likely cause of injury, instability or dysfunctional movement.
Through the process of Yoga, the ideal outcome for the pelvis is that it becomes free and stable. As someone who has a chronic anterior tilt eliminates their restrictions and weakness, they will be able to move freely between anterior tilt (useful for some forward folds and extreme backbends), neutral (walking position, Samasthiti, some standing positions), and posterior tilt (some standing positions, leg-behind-the-head asana). There would be a similar outcome for someone who began stuck in posterior tilt.
Moving from being stuck in one direction to stuck in another is not a healthy outcome.
First, let’s look at neutral alignment (Samasthiti):
A neutral position in the pelvis is one in which the ASIS is in vertical alignment with the pubic crest. The AIIS (anterior inferior iliac spine, the projection of bone between the pubic crest and ASIS) is also in vertical alignment, though it lies slightly behind the line. The coccyx is in horizontal alignment with the pubic symphysis (midway down the pubic bone – cannot be seen from side view).
The photo to the left shows an anterior tilt of 15°. It can be seen that the abdominal organs must now be restrained by the abdominal muscles and fascia. If this position is typical in a body, the psoas major is likely to become weakened due to being chronically shortened and tight (hypertoned). The weight of the body
At first glance, it is tempting to simply tilt the pelvis posteriorly. This will feel very stable and grounded through the pelvis, lower back, and torso. However, there are some complications. In Samasthiti — and many other Yoga positions — we are attempting to elongate the spine – increasing the distance between the sacrum and the atlas (the vertebrae at the top of the spine). Increasing the space between each vertebrae requires that the muscles of the back be relaxed, because muscles can only pull things together – in this case, the vertebrae.
The posterior tilt of the pelvis can be made using several different combinations of muscles. The most common engagement if you just hear “tuck your tailbone!” is to engage the gluteal muscles. As they contract, the gluteals pull down on the bottom-most fibers of the lower back, both the fascia (thoracolumbar fascia) and the muscles that arise from it (the erector spinae group). This creates a compressive effect through the lumbar spine, ‘squeezing’ the vertebrae together and down towards the hips and preventing them from elongating and lifting away from the pelvis. It can be seen in the above left photo that weight being transmitted through the spine would create a shearing force through the lumbar vertebrae; force would travel not only downwards, but also at an angle through the vertebrae, especially the topmost and bottommost of the lumbar vertebrae (chronically, this would be felt as a painful pinching). Furthermore, chronically tightening the gluteals and external hip rotators will exert a pull on the head of the femur, pulling it back and rotating it externally. This can often be observed as a continual splaying outwards of the feet while walking or standing. This position will strain the structures of the leg and foot.
A more suitable option for our goals is to use the deep abdominal muscles to lift the front of the pelvis upwards while keeping the gluteal muscles relaxed. This is one of the actions of uddiyana bandha — to lift and support the hips in a neutral position. Then, use the pelvic floor muscles to subtly draw the pubic bone and the coccyx together and gently down. This is a very subtle movement, almost a sensation of heaviness.
In a healthy body, a posterior tilt of the pelvis will not flatten the lower back. In the above right photo, a healthy neutral lumbar curvature is retained. The reciprocal muscle of the abdominals (rectus abdominis in particular) is the psoas major, which attaches to each of the lumbar vertebrae and travels through the interior of the pelvis to the top of the inner thigh. When well-functioning abdominals lift the hips to find a neutral pelvic tilt, the psoas will also help support the lower back and preventing its flexion. A minimum tension of the spinal extensor muscles will stabilize the spine from behind.
With this alignment, the lumbar spine will be balanced atop of the sacrum with a minimum of strain. The rib cage will be both lifted vertically (another action of the bandhas) and be supported by the dual action of the muscles of the front and back of the body. The entire spine will come into a series of four gentle, relatively shallow, counterbalancing curves.
When the pelvis is tipped anteriorly, the hip socket (acetabulum) and head of the femur come forward of the center of gravity, causing asymmetrical muscular engagement when walking and standing. The hamstrings, gluteals, and abductor muscles tend to shorten and engage when the pelvis is anteverted, while the quadriceps and adductors lengthen. This force is transmitted down the legs, often leading to a rotation of the knee and ankle. This can often be observed in the feet: the toes turned outwards, with weight resting into the outside edges of the feet (a healthy foot will carry weight through the inner arch).
In a neutral pelvic position, the feet and legs will be more directly beneath the center of gravity (slightly more forward relative to the pelvis), allowing the muscles of the outer leg to disengage and the psoas to participate more fully in the movement of walking, resulting in a lighter stride. Movement will be more integrated between the torso and lower limbs, as the psoas is one of the principle connectors of the two, allowing force to be communicated more effectively and the body to be in greater cohesion.
In addition to bringing the spine and the joints of the leg into alignment, neutral pelvic position benefits the complicated musculature of the pelvic floor and abdomen. The engagement of the outer leg and gluteals tends, over time, to widen the pelvic floor and weaken the pelvic floor muscles. With a anteriorly tipped pelvis, the organs must be supported by the abdominal walls, often observable as a sagging or distention of the belly or sides of the abdomen. If you visualise the pelvis as a basin or bowl (an oversimplification, yet largely truthful) filled with water, you can easily see that tipping the bowl forward will effectively decrease its volume as water would begin to spill over the front edge. In the same way, anteversion of the pelvis decreases its ability to contain and support the organs, displacing the effort of supporting the upper body from the bones and tight web of ligament and muscle at the pelvic floor to the less-suitable abdominal muscles and fascia.
There are many positions in which a full posterior tilt (including the use of the gluteal muscles) can be very beneficial — the engagement of the gluteals is not to be discouraged in many positions due to the alignment of the legs and/or the position of the body relative to gravity. Deep flexion is found the leg-behind-the-head asana and some arm balances, while a more mild posterior movement is found in the Utthita standing positions 3 Virabhadrasana (Warrior) poses. These are excellent examples of poses which require the effort of tipping the pelvis posteriorly. Although the effort is of strong posterior rotation, ideally the pelvis ends up in a neutral, floating position. It has the sensation of posterior rotation due to strong resistance of the psoas and hip flexors. They challenge the body in different ways, but all commonly create an anterior ‘sag’ in the lumbar spine, with severe anteversion of the hips – this is the body’s way of compensating for lack of strength (in the quadriceps of the front leg and the abdominals) or flexibility (in the quadriceps of the rear leg and psoas) by distributing the effort over multiple joints and muscles. Unfortunately, this tendency can create pain, instability, or tightness over time if left unchecked. By being mindful of pelvic position, and keeping the pelvis rotated posteriorly, you will maintain a strong, stable alignment and experience greater benefits from the pose.
Let’s look at Warrior I. Ideally, the spine will be in a neutral position with the gaze lifted just until the thumbs can be seen. The essential stretch here is not a backbend, but rather increasing the flexibility of the quadriceps and psoas of the back leg while strengthening the front leg. Eventually, for an advanced practitioner it ends up as a mild backbend focusing on length, with the arms lifted straight overhead (not pictured). However, when those relatively new to Yoga or in a bad habit focus solely on reaching the arms straight arm, movement tends to originate from “rib thrust” rather than shoulder movement. This has the result of creating a lot of compression in the spine, creating a dead and probably painful asana as pictured below left:
The photo to the left is an example of compensation.
The spine often moves in sections; as you can see in the photo to the left, the quadriceps & psoas of the back leg are tight, and have pulled the pelvis into an anterior tilt. It is apparent that the spine is moving in straight segments, rather than integrated curves. The bottom section of the spine (the sacrum) is moving with the back leg, projecting force forward at a 45° angle. The connection between the sacrum and the lumbar spine is the next point of mobility, and the lumbar spine moves as a unit for an additional ~15° of rotation.The juncture of the lumbar and thoracic spine is the most mobile spot in the torso, and there is a severe bend in the spine at this spot (“rib thrust”). Lastly, the cervical spine has fallen back to a 90° angle behind the body.
This means that the sacrum is facing almost the opposite direction as the cervical spine — each part of the spine is collapsing backwards, and working against every other part. This will create compression and pain, not to mention being an ineffective position to work with the deep hip muscles. Someone who regularly practices this position will no doubt have feelings of crunching and pinching throughout the spine.
A more stable solution is one in which the upper body remains neutral, and only the legs move (right side photo). Neutral does not mean relaxed, however. By finding a sense of grounding through the front of the ribs as the abdominal muscles engage (pull the bottom of the rib cage and the pubic bone towards the navel) and keeping the pelvis rotating posteriorly, you will keep the pelvis in roughly the same position as a standing posture, maintaining an effective base for the spine. Lifting the hips into a posterior tilt will ensure the muscles are lengthening or strengthening fully, and that the main work of the pose is not being displaced to the torso, where it does more harm than good. Note that although the effort is of strong posterior rotation, ideally the pelvis ends up in a neutral position. It has the sensation of posterior rotation due to strong resistance of the psoas and hip flexors.
The above right photo is a good solution to find a foundation in the pose. After that is established, the hips stay stable and over the course of some months, the ribs start to expand and lift while the shoulders open, moving towards a more expanded expression of the asana with a slight backbend, with the hands directly overhead and the gaze upwards.
Arm balancing asana are another place where posterior tilt is found. Stability and strength in Bhujapidasana and Bakasana involves a deep tuck of the pelvis and flexion of the spine.
The Ashtanga system has a large focus on leg-behind-the-head asana. If you practice these poses, you can start with a deep flexion of the spine and pelvis. Once the leg is in position, encourage a gentle counteraction of straightening the spine. Due to the structure of the hips, a slight flexion and rounding is not a problem. These are a family of flexion-forward-folds. If you’re able to practice these movements, the flexion is healthy.
An anterior pelvic tilt is useful for setting the body up for non-flexion forward folding positions and for the deep backbend family. In the primary series, this applies to all forward folds except kurmasana and supta kurmasana.
The principal action of forward folds is a lengthening of the entire back side of the body, from the heels through the backs of the legs, to the back of the spine all the way to the crown of the head. Anteriorly rotating the pelvis will ensure that the hamstring muscles are lengthening to their full capacity while simultaneously rotating lifting the pelvis to set the spine up for elongation. It’s common to see a very curved spine in forward folds for beginning practitioners. This typically results from tightness in the hamstring muscles, which pull the pelvis into a posterior rotation as they lengthen. The sacrum will be in a roughly vertical position, and each vertebrae bends a little bit more, from which the head hangs heavily. Focusing on rotating the pelvis anteriorly will be much more effective in correcting the pelvic imbalance than reaching for the toes and attempting to force the back down (which has the added negative of a high risk of back injury). As this tightness is released, the sacrum will rotate more and more, and the spine straightens. Eventually, the spine will be stay fairly straight and most of the motion will be initiated by the pelvis.
A well-functioning psoas major / rectus abdominis relationship is easy to judge in this position. When the spine is in flexion (folding forward), the navel should draw in towards the spine as the abdominals release. This movement can be furthered or reestablished by engaging the bandhas.
Observe the principles of biomechanics in both the seated and standing forward fold:
Posterior pelvic tilt curves the back as the head is ‘forced’ down towards the knees to deepen the pose. The effort through the arms plus gravity presses down on the spine at the junction between the thoracic and cervical spine. This force is transmitted down the spine to the junction between the thoracic and lumbar spine, ‘bulging’ the discs outwards. This is a very weak position for the spine, and can lead to injury. Note that regardless of whether there is pain, force, or energy, is pressing back through the discs, causing strain. This bulge may then become severe enough to warrant a medical diagnosis as a “disc bulge,” which is often diagnosed only if there is pain due to nerve compression. A disc herniation is of the same mechanical force but greatly increased severity, meaning that the hard outer shell of the disc has cracked and the soft, gel-like center leaks out.
Folding in this way will never quite result in a complete forward fold, as the sacrum is not involved with the movement. The head may come closer to the knees over time, but a substantial gap will always remain.
A healthier pattern to practice in forward fold is to create an anterior tilt in the pelvis. By lifting the sacrum and rotating the pelvis anteriorly, the practitioner creates a smooth, integrated transfer of force through the spine as a unit, by rotating the sacrum and lower back to be in the same plane of force as the thoracic and cervical spine. Extending through the crown of the head elongates the spinal column as the navel and rib cage move towards the thighs. To get a feel for this (unless you have a neck injury), look up and forward – the sections of the spine move in relation to each other in order to keep balance; looking up will move the rib cage toward your legs, which is a synergistic movement for forward folds.
Forward folds from standing (as in the Sun Salutation sequence) work in much the same way.
In both cases we are attempting to lengthen the spine towards the toes. To perform this position effectively, ensure that the mechanics of your body is working with you, not against you.
If you’re practicing the intermediate or advanced series (or the poses from those series, if you practice a different style of Yoga), an anterior tilt of the pelvis is necessary for the deep backbends. Urdhva Mukha Svanasana (upward facing dog), and bhujangasana (cobra), however, are mild backbends which benefit from a slight posterior movement of the hips. In the practice of deep backbends like ustrasana, laghu vajrasana, the kapotasana family (including raja and eka pada), urdhva dhanurasana, and dropbacks, draw the sacrum in and up. Keep drawing the coccyx and pubic bone together and slightly down to narrow and stabilize the pelvic floor. The lift of the sacrum in and up creates a chain of lift and strength up the spine, allowing a more even backbend and opening of the thoracic spine. Often Yoga practitioners are told to drop or tuck the sacrum in backbends. Unfortunately, this puts a lot of stress on the SI joint and the sacro-lumbar junction, leading to the reputation these poses have for pain or injury. It also locks the thoracic spine, making it much more difficult to expand the ribs. Dropping (posterior tilt) the sacrum opposes the movement of extension in a backbend, creating strain and stress.
Experiment for yourself. In a standing or kneeling (ustrasana) position, take your hands all the way back to your sacrum and squeeze the elbows lightly together. Lift the sacrum up into your hands and give a slight force of resistant, pressing into your hands. Use that force to lift the ribs up towards the ceiling and lengthen the spine.
Then try the opposite: tuck the tailbone. Which feels more conducive for you to start a backbend? (Hint: in my body, tucking the tailbone is agonizing and injurious during a backbend.)
This is only an introduction. Take what you’ve learned here to any other Yoga pose — see how it fits, and find a method that works for you. Pelvic tilt has a dramatic impact on the entire body, and a small difference of only a fraction of an inch could make the difference between reinforcing patterns of resistance in your body or performing an asana effectively.