Updated: Oct 1, 2020
The spine is made up of individual vertebrae connected by intervertebral discs at the front and facet joints at the back. It is separated into sections:
Cervical spine (neck)- 7 vertebrae
Thoracic spine (mid back)- 12 vertebrae
Lumbar spine (lower back)- 5 vertebrae
Sacrum- one fused section of 5 sacral vertebrae, linking up with the iliac crests to make up the pelvis
Coccyx- 4 fused coccygeal vertebrae
Why do we have a spine?
1) Supports us in an erect posture
2) Protects our spinal cord
3) Allows movement of our head and body
4) Attachment site for muscles
5) Enables respiration
Kyphosis and lordosis:
The spine is curved in certain ways in certain regions. Our thoracic spine and sacrum reflect how we were shaped as embryos and are rounded into a kyphosis. Our cervical and lumbar spine curves are secondary curves, formed as we start to develop and walk, and are shaped into a lordosis. The curves function to act as shock absorbers, providing strength and elasticity and preventing fractures.
The degree of these sagittal (front to back) spinal curves can vary a lot from person to person. Sometimes this is a variant from birth (congenital) and may be genetic. Some people have functional changes in these curves secondary to postural faults, muscle imbalances or compensation from issues in regions above or below. Other people develop structural changes in these spinal curves secondary to other conditions such as osteoporosis (often seen in post-menopausal women), spondylolisthesis (slippage of one vertebra over another, often seen in the lower lumbar spine) or Scheuermann’s disease (seen in adolescents).
Anterior and posterior pelvic tilt:
Another way many chiropractors and other musculoskeletal specialists may assess patients is to look at pelvic tilt and whether it’s more forward (anterior) or backward (posterior). This may be assessed in different positions such as standing, sitting and lying down or with specific sports movements.
To roughly assess this yourself:
Stand sideways on, next to a mirror. Find what a lot of people call their ‘hip bones’ on either side (this is actually the top of your iliac crests of the pelvis). Run your fingers forward until you feel the most prominent and forward (anterior) bit of the pelvis. This is called your ASIS (anterior superior iliac crest). Now run your hands from the sides all the way to the back until you feel what some people call the ‘dimples’ or protrusions at the bottom of your lower back. These are called your PSIS’s (posterior superior iliac crests). Put one thumb on the ASIS and another on the PSIS on the same side closest to the mirror and stand as naturally as you can.
Is the front thumb much lower than the back thumb… in which case you may have a more excessive anterior pelvic tilt. Is the front thumb only slightly lower than the back… in which case you may have a fairly neutral pelvic alignment (it is considered ‘normal’ for us all to have around 5-10 degrees of anterior tilt). Or are they fairly level/is the back lower than the front… in which case you may have a more excessive posterior pelvic tilt.
The tilt may even vary from left to right side depending on a number of other factors down the kinetic chain such as leg length inequality/foot imbalances... but it could be a chicken vs egg situation of what came first!
How this may relate to your surrounding muscles:
Anterior pelvic tilt may be associated with tight/overactive hip flexors and lumbar erector spinae muscles (either side of the lower back), with weak/underactive abdominals and glutes. This is what is also described as lower crossed posture.
Posterior pelvic tilt may be associated with tight/overactive abdominals and glutes, with weak/underactive hip flexors and lumbar erector spinae muscles.
Exercises that focus on sagittal spinal mobilisation:
Here’s a couple of simple exercises that focus on pelvic tilt and spinal mobilisation…
These are often easiest to learn lying on your back with the knees bent up (feet on the floor). From this position, is there a gap between your lower back and the floor? (This may again give an indication as to the natural position of your pelvis usually). If you naturally have an increased lordosis and/or anteriorly tilted pelvis, posteriorly tilting your pelvis to close the gap between your lower back and floor may feel relieving. Feel your abdominal muscles and glutes working as you do so and hold the posterior pelvic tilt for around 5-10 seconds before slowly relaxing off. Repeat this tilt up to 10 times.
You can do anterior/posterior pelvic tilt mobilisations sitting, to allow you to try and find a more ‘neutral’ spinal alignment when sat at your desk at work, for example. You may also progress to doing them standing.
On all four’s (hands aligned under the shoulders and knees under the hips) slowly arch your back towards the ceiling and hold at your comfortable maximum stretch for around 5-10 seconds. Then dip your lower back down towards the floor, holding again for 5-10 seconds if comfortable. Repeat this 10 times.
(Ideally, I would recommend doing these after being assessed by a musculoskeletal professional. Generally I find these easy and safe exercises for most people, however, I’d advise seeking further advice before continuing with these if they cause or exacerbate pain).
What's the relevance? Important concluding points...
Static observations like these are just one way we build an overall picture of what may be going on in each individual case. They provide one small piece of the puzzle. Postural observations such as this (and static imaging results) do not always govern function or indeed pain levels! For some patients, having an exacerbated anterior/posterior pelvic tilt may actually be benefiting and not hindering them. That’s why we don’t assess this in isolation. Instead, putting together these factors, alongside functional movement and muscle testing, neurological testing, palpation and knowledge of other factors such as psycho-social influences, nutrition, exercise and sleep, helps us better understand what may be causing each individuals complaints.