It’s simple!
Because you posteriorly tilt your pelvis.
There are many reasons that we do this:
- Fear
- To lengthen our low back
- To protect the low back
- Your teacher told you to do it like that… etc.
Our body moves in patterns. How you move your pelvis will not only effect your lumbar spine (it’s called the lumbopelvic rhythm) but it also determines how our arms and legs move.
When you tip your pelvis forward (anterior) your low back curve (lordosis) increases, your whole spine arches into a backbend and your legs internally rotate. The opposite happens when you posteriorly tilt the pelvis. The low back loses it natural lordosis and flattens out and your whole spine rounds into a kyphosis. And the legs externally rotate.
It’s a whole-body kinematic movement pattern.
If you have no compression, discomfort or pain when you anteriorly tilt the pelvis, this is the easiest way to keep your feet straight. It puts your whole spine into a backbend, which means it also opens your chest. This makes backbending light and easy.
One reason to not anteriorly tilt your pelvis iis if you experience compression in your low back and it causes you discomfort or pain. Then a NEUTRAL pelvis is ideal. From here you can still prevent posteriorly tilting the pelvis and the external rotation of the legs that comes with it.
Posteriorly tilting the pelvis and then doing a backbend means you will hinge in the low back at L4/5 and L5/S1 instead of being able to distribute the arch more evenly over the low back and thoracic spine. These two segments already move the most into extension (backbending) and they also already incur the greatest wear and tear in your low back.
Not posteriorly tilting the pelvis does NOT mean not using your gluteal muscles to extend your hip joints. It means not using glute max to posteriorly tilt your pelvis! Read my other blogs ‘Why Use Glute Max for Backbends’.
It can be difficult changing our movement patterns but watch those who can keep their feet straight and notice their pelvic position. Or look at young gymnasts who backbend with ease and grace and you’ll see, they all anteriorly tilt their pelvis!
Always with you on the mat
Monica