Mel Siff
10-26-1998, 08:40 AM
Replies to the issue of spinal manipulation imply that balance and symmetry of
structure and function of the human spine are as precise as that of a high
speed mechanical engine in which even minor deviations from engineering
specifications can have serious consequences.

Living organisms generally have reasonably generous 'safety factors' hardwired
into them to facilitate survival and adaptation as self-regulating and self-
repairing systems. If tolerances were to such a high degree of precision, this
would not augur well for the persistence of life under such a wide range of
environmental and operating conditions.

Homeostasis is far more dynamically 'fuzzy' than statistically determinate,
as is implied by current theories of 'imbalances' being major causative
factors in pain, disability and disorder. If such precise calipers,
goniometers etc are used to identify and measure deviations of posture or
alignment, it would be interesting to ask which norms and tolerances need to
be adhered to and to what extent individual structural idiosyncracies are
accepted. For instance, is sagittal linearity of the spine a sine qua non of
healthy human function.

The entire issue of imbalances, subluxations and other concepts of deviations
for generalised norms and a fairly deterministic relationship between
structural and functional mechanisms seems to be central to physical therapies
such as chiropractic. What about the possibility that conditioning by
repeated exposure to 'reasonable' stresses or intentional physical training
increases the magnitude of the inherent safety factors of the human body, as
seems to be implied by the continual increases in human sporting performance?

Is one justified in assuming that the safety factors of the human body are
statically invariant and of such a small magnitude that even minor deviations
from hypothetical norms may precipitate serious pain and dysfunction, not only
in the architecture of the body, but also in remote physiologically functions?

Dr Mel C Siff
Littleton, Colorado, USA

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