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We observed that cervical lordosis decreases, on
average, only 0,6° between the 12th and the 20
th
week of gestation, while from the 20
th
to the 32
nd
week it increases, on average, 2,2° and on the 37
th
week it decreases again, on average, 1,6°.
In relation to dorsal kyphosis, we observed that
the angle at the 20
th
week of gestation begins
increasing, on average, 1,3°, at the 32
nd
week it
decreased, on average, 3,5° and at the 37
th
week
continues to decrease with a smaller amplitude, on
average, only 0,1°.
Relative to lumbar lordosis, we observed that the
angle decreases at the 20
th
week, on average 4,6°, at
the 32
nd
week increases, on average, 4,3°, and at the
37
th
week we found that it continues to increase
(2,1°).
We concluded that, between the 12
th
and the 37
th
week of gestation, the angle of lumbar lordosis and
dorsal kyphosis, on average, increases 1,8° and 2,4°,
respectively. On the other hand, the angle of the
cervical lordosis, on average, decreases only 0,1°.
Applying the linear regression correlation
significance test from one moment of evaluation to
the next, we noted that there are no significant
differences in the angle of curvature throughout
pregnancy, except for lumbar lordosis between the
12
th
and the 20
th
week of gestation (p<0,05).
During data collection, and only through clinical
observation, we assumed that the difference of the
angles between two successive moments could be
different throughout pregnancy. Due to the absence
of studies in this domain we decided to compare the
difference of the angles between two consecutive
moments of evaluation, with the homologous
difference between the two moments of evaluation
immediatly after. We oberved that there is a negative
correlation (p<0,001).
We conclude that when the angle of curvature
increases between the 12
th
and 20
th
weeks of
gestation, it diminishes between the 20
th
and 32
nd
weeks and increases again between the 32
nd
and 37
th
weeks of gestation.
On the other hand, analysis of the data raised
doubt relative to the amplitude of the angles
throughout pregnancy.
To test this hypothesis, and taking into account
the angles registered in two consecutive moments,
using as reference the 12
th
week, two groups of
pregnant women were formed: one where the angle
increases between two consecutive moments;
another where the angle decreases between those
two moments.
We compared the angle of each of the curvatures
in the four moments of evaluation and we observed
that there are significant differences in the two
groups in the various moments, relative to all the
angles. We observed, for example, that the average
of the angle of lumbar lordosis at the 12
th
week is
the following:
• 36,9° (IC95% 27,0–46,8) – group of women
where the angle increases from the 12
th
to the
20
th
week
• 50,6° (IC95% 41,4–59,8) - group of women
where the angle decreases from the 12
th
to the
20
th
week
We conclude that, although there are no
significant differences in the angles of curvature
throughout pregnancy, we saw that those same
angles oscillate in a significant way throughout the
gestation period. That is, when they increase from
the 12
th
to the 32
nd
week, they decrease from the 20
th
to the 32
nd
and increase again from the 32
nd
to the
37
th
week of gestation.
We also noted that the referred alteration in the
angle form the 12
th
to the 20
th
week behaves in the
opposite way taking into account the angle that each
pregnant woman presents on the 12
th
week. Thus, for
example, if the average value of the amplitude
identified in the first moment of evaluation is 50,8°,
we observe that that angle will decrease in the
following period, increasing again in the following
one.
5 CONCLUSIONS
With the building of Vertebral Metrics – innovative
instrument for a global evaluation of the spinal
column, we produced for the first time a systematic
and global study of the spinal column that
contemplates the characterization of the amplitude
of its angles of curvature.
In reality, the inexistence of studies that evaluate
simultaneously the angle of the three curvatures of
the spinal column at the same temporal period, limits
in a certain way the comparability with other
analyses, however it transforms this work in a
reference in the Health area. As far as we know this
is the first investigation that approaches in an
integrated way the spinal column in its totality. Lack
of consensus will probably be related to three crucial
variables:
• the small number of quantitative studies;
• the methodology applied in the data collection;
• the not very expressive number of pregnant
women involved in the majority of quantitative
studies.
BIODEVICES 2012 - International Conference on Biomedical Electronics and Devices
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