Yoga Anatomy

28 Yoga anatomY

After crawling and creeping like
our quadruped ancestors, in order
to bring our weight over our feet
we must acquire a lumbar curve. So,
at 12 to 18 months, as we begin to
walk, the lumbar spine straightens
out from its primary, kyphotic curve.
By 3 years of age, the lumbar spine
begins to become concave forward
(lordotic), although this is not out-
wardly visible until 6 to 8 years of
age. After the age of 10, the lumbar
curve fully assumes its adult shape
(figure 2.13).
The full glory of nature’s ingenu-
ity is apparent in the human spine,
perhaps even more so than in other vertebrates. From an engineering perspective it is clear
that we have the smallest base of support, the highest center of gravity, and the heaviest
cranium (proportional to our total body weight) of any other mammal. As the only true
bipeds on the planet, we are also earth’s least mechanically stable creatures. Fortunately,
the disadvantage of having a cranium as heavy as a bowling ball balancing on top of the
whole system is offset by the advantage of having that big brain; it can figure out how to
make it all work efficiently, and that’s where yoga can help.
Our human form in general, and our spines in particular, exhibit an extraordinary reso-
lution between the contradictory requirements of rigidity and plasticity. As we shall see
in the next section, the structural balancing of the forces of sthira and sukha in our living
bodies relates to the principle of intrinsic equilibrium, the deep source of support that can
be uncovered through yoga practice.

elements Of linkAge

Between tHe verteBrAe

The spinal column as a whole is ideally constructed
to neutralize the combination of compressive and
tensile forces to which it is constantly subjected
by gravity and movement. The 24 vertebrae are
bound to each other with intervening zones of
cartilaginous discs, capsular joints, and spinal
ligaments (shown schematically in blue in figure
2.14). This alternation of bony and soft tissue
structure represents a distinction between passive
and active elements; the vertebrae are the passive,
stable elements (sthira), and the active, moving
elements (sukha) are the intervertebral discs, facet
(capsular) joints, and a network of ligaments that
connect the arches of adjacent vertebrae (figure
2.15). The intrinsic equilibrium of the spinal column
can be found in the integration and interaction of
these passive and active elements.

E5267/Kaminoff/fig2.14/417589/alw/pulled-r2

Birth3–9 months1–3 years6–10 years

Figure 2.13 Development of primary and secondary

curves.

E5267/Kaminoff/fig2.15/417590/alw/pulled-r1

Figure 2.14 Alternating zones of hard

and soft tissue in the spinal column.