What is posterior pelvic tilt and how does it relate to back pain? To understand this, it is helpful to first identify the normal position of the pelvis as well as what we mean when we’re referring to pelvic tilt. From there we can fully appreciate the implications this will have on the lumbar spine especially if we’re suffering with lower back pain or sciatica.
What is normal pelvic alignment?
In order to fully grasp the normal pelvic alignment we must cover why it is of interest in the first place. For reference most of these comments are referring to our spine and pelvis as we look side-on, standing upright. We should under normal circumstances see that the lumbar spine is positioned above the hips. This allows for the efficient transfer of force through the body when standing, or sitting for that matter. In the cases of the latter, the weight is transferred into the sitting bones and then into the chair, instead of through the hips into the lower limb.
In this normal position, there is a slope formed by the sacrum or “tailbone”, you might have heard this region mentioned as S1, the first sacral vertebra. This slope has a specific angle compared to the horizontal which allows for the right balance of give, and stability as the lumbar spine transitions into the sacral section of the spine through the slightly wedged L5, S1 disc.
When we move our pelvis posteriorly, thinking of a posterior pelvic tilt or a posterior pelvic tuck, we flatten out that angle at the sacrum making it closer to horizontal, this has a number of consequences which we’ll get to later. When we anteriorly tilt our pelvis, we find that the slope that your low back is “sitting on” becomes more steep.
This alignment in the static position is maintained by a balance of ligament tensions and rigidities. Having said this, the slope can be influenced in all of us in a less discreet manner by pulling on the muscles of the hips. Posterior pulleys like the hamstrings will pull the pelvis into posterior tilt and anterior pulleys like the psoas muscle will pull the pelvis into anterior tilt. Other muscles can also play a role in the movements we’re talking about here, such as your low back muscles and your rectus abdominus – the 6-pack. There is also an important balance between these muscles that allows for effortless balance to be achieved in the various upright static postures – standing or sitting.
How do we measure pelvic tilt?
Many a time members will join the program, or in years gone by, patients in the clinic visit us having been told they’ve got posterior pelvic tilt or that they need to do posterior pelvic tilts to undo an anterior pelvic tilt, and that this is influencing their back pain. The fact of the matter is, that in the majority of these cases there has only been a rudimentary physical examination, perhaps a comment that the glutes stick out more or less and therefore the individual has a pelvic tilt one way or the other.
The problem is that these measurements are often wildly inaccurate, for example, the way in which our muscles, fat and skin hang over our skeleton, amongst many other things such as the exact position of the measurements on the bones all play into the accuracy of the measurement. Then on top of that, there is the natural variation in the position of the sacrum and the hips within the pelvis – this is a permanent measurement and cannot be changed. Often those that do not work with imaging are unaware of these nuances below the surface of the skin, yet they have a huge impact on the true pelvic tilt.
The biggest danger is that conclusions from these measures are made and patients take them on board, therefore pinning the badge of anterior or posterior pelvic tilt to their chest. A badge that is often very difficult to take off!
Measuring the most important aspect of pelvic tilt, the sacral base referenced earlier is the best way to get an idea of how the pelvis’ position is playing into a lower back problem, how this person is load bearing, and the consequences for their back pain or sciatica.
The important thing for most to recognise however, is that most of us are normal, and do not need to get caught up in the nuances of pelvic tilt, it often only serves to be an unhelpful focus that we have little practical control over and end up trying to fix issues that aren’t broken. This has the effect of detracting from exercises and practices that will help us!
What is the role of posterior pelvic tilt in back pain
We mentioned earlier that the posterior pelvic tilt is a movement that impacts the lumbar spine, and it does so in 3 important ways, especially important if you’ve been suffering from lower back pain.
When you tilt your pelvis posteriorly these things happen:
- You flex the lower lumbar spine, relative to the neutral because all things are connected, this “flexion” or “forward bending” is most pronounced at the L5, S1 junction and then less so at the L4, L5 junction.
- As your sacrum is flattening out, the flexion leads to an increase in loading through the discs, the front part of the vertebral unit, the two aforementioned junctions being the most common sites of disc injuries – herniations or bulges etc.
- The sacroiliac joints are relatively disengaged, meaning there is a little more give in them – making them more exposed to stress and strain.
Typically those with lower back pain will have injured their back in a load bearing scenario and/or load bearing becomes a challenge – even provoking pain. That will be because the spine is having pressure put through it. If we think about the positions that the spine would be happy to load bear in for a moment we see the problem.
Under load, the sacroiliac joints want to be engaged, as they form an inverted keystone, and when engaged, the rough fibrous parts of the joint become “locked” into position ready to transfer force, the lumbar spine itself will consequently want to spread the load effectively through the discs on the front, and the facet joints on the back, approximately 70% of load through the discs and the remaining 30% through each of the facet joints. The lumbar spine being in neutral, puts the muscles in a primed position ready to bear the load and everything works nicely.
Everything about the posterior pelvic tilt moves us away from this ideal, creating vulnerabilities, through instability in the case of point 3, the sacroiliac and point 1, the position of flexion, as well as focusing all of the load through the discs. Consequently, we create instability around an injured segment, which we drive 100% + of the load through.
Why are pelvic tucks recommended so often if they’re so bad for back pain?
Although some have severe herniations in the lower lumbar discs, because of the way in which most of us injure our lower back, compression is a significant factor almost always. This results in our discs becoming injured even if not severely as mentioned above. This will often be in conjunction with the ligaments of the lower lumbar spine that reinforce and complement the disc being involved in the injury. Thus the creation of instability at the level of the low lumbar spine.
This is pretty unremarkable; most injuries are characterised by a loss of normal stability at the level of injury whatever the joint!
There are two real reasons for the pelvic tilt being recommended. Firstly, inflammation builds up in the injured region, creating congestion around the spine, this fills up some of the bony holes and creates symptoms, from aching to pain in the low back and glutes, or sciatica down the leg. By doing a pelvic tuck, the flexion that we mentioned earlier has the effect of increasing the size of those holes, therefore reducing the feeling of the pressure building up in the area. This however does little to help the underlying problem, only serving to reinforce a pathological practice due to the momentary relief it may well provide.
The second reason pelvic tucks are recommended is in classes like yoga and pilates when a core exercise, typically involving the legs, is being done. By tucking the pelvis as far as you can, you pressurize the lower back and this decreases the likelihood of the back arching uncontrollably when raising the legs. This is however, nothing but a blunt tool.
By unwittingly teaching hacks to avoid irritating the back in one direction, arching & jaring the back painfully, you are not teaching the ability to stabilize the lumbar spine in neutral. The person on this path will only be able to habitually engage with a pelvic tuck, and therefore, this will often be carried through to standing practices.
Standing with a load – revisit the earlier section on what happens when doing a posterior pelvic tilt – not conducive with effective load bearing and only serves as another habitual barrier to recovery.
Can’t you just stretch your hamstrings to resolve posterior pelvic tilt?
Kind of. Most of us spend large amounts of our days sat down, in a posterior pelvic tilt position no less. The hamstrings are a small part of the problem, hip flexor weakness is a second. Let us just propose that you did perfectly strengthen your flexors and stretch your hamstrings. You can do this relatively quickly. But if you do not address the fact that you’re sitting every day in bad positions, and moving every day in inappropriate ways, you will struggle to make lasting change. You need to focus on the lower back healing first.
If you’re absolutely set on pelvic tilt, make sure you have had it measured and know exactly how tilted you are, with load bearing X-ray imaging no less. Anything short of this is a complete waste of time and you’ll likely do more harm than good.
Even once you’ve identified this, focusing initially on the health of the lower back, providing strength and stability to the lower back so effective healing can take place. Being more conscientious on a daily basis will be an essential change too. Over time, your lower back will heal up, and you’ll find some of the neurological loops, such as sending signals to the hamstrings, abate. At this stage, you can start working, alongside your strengthening, on some fine tuning of the pelvis and lower back alignment and an effective return to normal alignment.
Should you ignore pelvic tucks for back pain?
For most of you reading this far, if you’ve got lower back pain, focus first on getting the foundational strength, control and habits in place. The Phases we teach in the Back In Shape Program are exactly the right course of action to build what’s required to fix your lower back pain. No pelvic tucks required! And for the very small minority of you who do have some objective, measured discrepancy at the level of the pelvis that is significant and not minor, we can help you with a little extra guidance to fine tune the rehabilitation process later on.
Comment of the week – Amanda
“BIS will continue to be part of my daily routine to future proof my back and neck into older age.”
3 Steps For An Injury First Approach To Fixing Posterior Pelvic Tilt:
- Create spinal stability
Integrity in your spine itself is a vital first step, and this will extend into the position of the pelvis. Without static strength and control you’ll have little luck holding the spine and pelvis in neutral at any rate. Secondly, until you’re able to achieve this, your back injury will have little chance of properly recovering. The consequence of this is that signals will constantly be going into the hamstrings telling them to tighten up, making lengthening the hamstrings in any meaningful way the equivalent of 2 steps forward 2 steps back!
- Modify your daily activities
How you use your body on a daily basis plays a huge role, now you can consciously control you neutral spine, you can start applying this to all the times in the day where you’re unwittingly rocking into a posterior pelvic tilt. Sitting makes up a huge part of daily life for many of us, this creates a great opportunity to make positive change. It is simple and easy to maintain the neutral spine, the difficulty is in the consistent self-awareness. Build the habit and it will eventually become effortless.
- Work on the muscle component
This becomes last for a reason! Exercises to strengthen your hip flexors as well as lengthen your hamstrings are the basics, but also the lumbar erectors which are so often chronically lengthened. Exercises like the dead bugs in Phase 1, as well as the hip hinges and hip flexor exercises later on in the program will achieve these goals and if you need to focus a little more on one or two of these you can always reach out to us in the community to help guide you.