Yoga Anatomy

32 Yoga anatomY

push–Counterpush

The movements of fl exion, extension, and lateral fl exion produce asymmetrical movements
of the nucleus, but the result is the same: Wherever the vertebral bodies move toward each
other, the nucleus is pushed in the opposite direction, where it meets the counterpush of
the annulus, which causes the nucleus to push the vertebral bodies back to neutral (see
fi gure 2.22).
Assisting in this counterpush are the long ligaments that run the entire length of the
spine, front and back. The anterior longitudinal ligament runs all the way from the upper
front of the sacrum to the front of the occiput, and it is fi xed tightly to the front surface
of each intervertebral disc. When it is stretched during backward bending, not only does
it tend to spring the body back to neutral, but the increased tension at its attachment to
the disc also helps to propel the nucleus back to neutral. The opposite action occurs in the
posterior longitudinal ligament when it is stretched in a forward bend. It runs from the back
of the sacrum to the back of the occiput.
Every movement that produces disc compression in the anterior column necessarily results
in tension to corresponding ligaments attached to the posterior column. The recoiling of
these ligaments out of their stretched state adds to the other forces of intrinsic equilibrium,
which combine to return the spine to neutral.
Note that all this activity occurs in tissues that behave independently of the circulatory,
muscular, and voluntary nervous systems. In other words, their actions do not impose an
energy demand on these other systems.

E5267/Kaminoff/fig2.23 /417598/alw/pulled-r1

Figure 2.22 (a) Flexion and (b) extension movements produce asymmetrical movements of the
nucleus, which, under pressure from the annulus, returns to a central position, thus helping the
spine to return to neutral.

a b