When you’re settled into a comfortable meditative sitting position with your pelvis tilted slightly forward, you can turn your attention to straightening your back. Of course, straight is a misnomer when used to refer to the spine because a healthy spine actually has several distinct curves: one at the lumbar region or lower back, another at the thoracic area or midback, and a third at the neck or cervical spine.
Unfortunately, these natural curves are often exaggerated by the demands of computer workstations and other sedentary environments, and you get into the habit of sitting hunched over, with your shoulders rounded, your upper back collapsed, and your neck and head craned forward like a turkey vulture.
You may not be able to reverse sitting habits like these in a few sessions of meditation, but you can experiment with extending your spine — a more accurate term than straightening — and slowly but surely softening those curves back to their natural, graceful arches. You may find yourself carrying these new sitting habits into your other activities so that in time you’re gently correcting your posture.
Try one or all three of the following visualizations to help you discover what a straight or extended spine feels like. The important thing is how your body feels from the inside. You want to feel centered, stable, grounded, and aligned with the force of gravity.
Suspending your head from a string: Imagine that your entire body is suspended in the air from a string attached to the crown of your head. As you feel the string pulling your head up into the air, notice how your spine naturally lengthens, your pelvis tilts forward, your chin tucks, and the back of your neck flattens slightly.
Stacking your vertebrae one on top of another: Imagine your vertebrae as bricks that you’re stacking one on top of the other, beginning with the first at the base of the spine. Feel your spine growing up toward the sky brick by brick, like a skyscraper.
Sitting like a mountain or tree: Imagine your body as a mountain or tree with a broad base that extends deep into the earth and a trunk or peak that reaches toward the sky.