Ida Rolf wrote that the characteristic of a well-integrated body is a sense of lift.
What does that mean?
This post contrasts the effort to be erect with no-effort to be erect and in so doing, debunks misconceptions about good posture.
The Myth of Spinal Curves
Yes, the spine has four natural curves. However, the significance of those curves isn't that the spine has them, but that the spine can have them. The curves change with movement and general tension level. What makes the curves change is muscle tension in the spinal muscles, which pull on the vertebrae and change their positions, and in the legs, which pull on the pelvis and change spinal curvature at the connection of spine-to-pelvis, above.
Here's the thing: Your spine consists of vertebrae that are not square, but trapezoidal (except for one: L4, which is "square" -- meaning that the upper and lower surfaces are parallel). "Trapezoidal" means that the upper and lower surfaces have different slopes. It is the meeting of the upper and lower sloped surfaces of neighboring vertebrae that gives the spine its curves -- but those slopes are separated by discs that have a certain elasticity, so the curves change with movement. So, the myth is that the spine has a certain amount of curve or that their is a "normal" amount of curve. Curve, in a healthy person, changes from moment to moment; only in an unhealthy person are the curves fixated.
Now, even though the spine has curves, the spine can feel straight. That happens when the upper and lower surfaces of neighboring vertebrae meet squarely, and that happens when the spinal muscular tensions are balanced to arrange them that way and to make that arrangement the "home" position to which a person naturally returns in movement.
The feeling is of being effortlessly supported, balanced, and uplifted -- poised. In the literature of Tibetan Yoga, the description is of the spine "feeling like a stack of coins" -- a description that applies to sitting or standing positions, but not to action. So, the description has that limitation and in any case, these words can't mean much of anything to you unless you've experienced the feeling, so we have to leave it at that.
Now, here's an oddity of human beings: In order to feel strong or supported, people adopt efforts or various kinds. We tend to think we have to.
What happens, then, is that spinal muscles contract, pull on vertebrae, shorten the spine by compressing discs, and change the alignment away from effortless support or equilibrium.
In that way, people substitute "strength" for balance.
So, whereas a person whose back muscles are balanced feels supported and balanced from within, the person whose back muscles are tight feels "strong" -- at the expense of that sense of support, balance or effortless lift. They also feel tired, sore, and stiff.
People are endlessly trying to conform to various ideas and standards, and in so doing, they are adding stress to themselves, to their back muscles, and sacrificing balance, effortless support, and lift.
People are also endlessly experiencing stress, anxiety, guilt or shame (variations of cowering), all of which trigger the muscles of the front to tighten and the spine to bow forward. In order to counter that condition of cowering, people must tighten their backs, and counter cowering with "indomitable will" or "self-righteousness".
That condition (co-contraction of front and back), shortens the spine, literally compresses discs, and robs people of their sense of support, of equilibrium, of lift; their spine is not fully erect. We're left with pressure and stress, the experiences of "indomitable will" and "self-righteousness", which we may take as inevitable, right, or necessary.
It's clear that back pain is as much psychological as it is physical. Both aspects must be addressed for a fully erect spine -- for a person to stand at full stature, which is to say, feeling supported, balanced, and uplifted. It is also clear that departures from "good alignment" or good posture are as much a matter of misguided effort evident as muscular tensions as of objectively observable misalignments and their clinical consequences.
Although the psychological aspect I've noted above must be addressed on its own terms, the residual effects of stress and back tension can be dispeled. For more information on that topic, please see
which have audio and video links.