An average person needs to un-learn flexion and learn extension.
I used to think that until I started learning more of the intricacies of posture. Posture, imo, can be thought of as how we orient our skeletons in space to keep our center of mass over our base of support, so we don't fall over.
I think there's a lot of people who have too much kyphosis of the thoracic spine, but that can often be tied to anterior pelvic tilt, which is tied to lumbar extension. If the hips dump forward (for whatever reason) the only way you can stay upright is to hinge backward through the back (lumbar extension/lordosis). Then the only way to keep the head in a place where you can function is to crane it forward.
Then there's "swayback posture," in which the pelvis can be stuck posteriorly tilted, causing the ribs to shift back in space, and also maybe causing the lower back to lose some of its lordosis. Since the ribs shift back, just like with the above example, neck has to crane forward.
Then, there's the crowd that thinks flexion is the devil, and they spend all their time in extension, which creates its own problems by compressing the back. The thoracic spine is stuck
too straight (yes) and thus the ribcage is stuck in a "flat" position posteriorly, and the ribs themselves are in an externally rotated position (they are stuck in the "inhaling" position). This puts the diaphragm in a lengthened. stretched position which makes it harder to contract. Since it can't contract well enough, the person might end up using neck muscles to breath in an effort to expand the ribcage, where the lungs are located. The flat upper back can also lead to shoulder issues, since the scapulae cannot effectively glide on it anymore.
All that is to say that it's not as simple as "flexion vs extension." It's certainly not as simple, imo, as "flexion bad, extension good." As Conor Says in the videos, there's not as strong a correlation as you might think between "bad" posture and pain.
I think these videos do a good job of outlining the basic principles I wrote above. Conor is a younger guy, but notice that he never makes ubiquitous statements, outlines scope of practice, and highlights nuances.
This is about swayback posture, but the first 5-ish minutes outline many of the principles I wrote out above.
As I outlined in a previous post, if you
have to hinge at the hips
without letting your spine bend to do anything, you have
lost movement in your body.
Lastly, I've brought this up elsewhere on the forum, but it is interesting to note that the facet joints of the lumbar region only allow flexion and extension.... The lumbar spine is meant to have less mobility than the rest of the spine, but it is not meant to have
zero mobility.
Original Editor - Rachael Lowe
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