Sitting pressure was measured with the Force Sensitive
Application version 4.0 (FSA 4.0) (Takano Inc., Nagano).
The system consists of a thin mat with 256 strain gauge
sensor units. The data were sampled at a frequency of
5 Hz. The sitting pressure was continuously displayed on
the monitor to both the experimenters and the subjects. A
sensor was put on the skin surface of the 1st lumbar process
and sacral vertebrae. Elevation and roll angles of L1 were
recorded by 3-Space ISOTRAK (Polhemus Inc., Colchester)
during forward flexing and lateral bending. Position (x, y
and z coordinates) was recorded by 3-Space ISOTRAK at a
sampling frequency of 12.5 Hz. The analysis was performed
for all subjects. For measuring sitting pressure, each value of
the affected and unaffected side was divided by the sum of
the bilateral sitting pressures. To show the involvement of
affected and unaffected sides, we calculated the proportion
of the sitting pressure on each side. If the pressure were
symmetric, each side would be 50%.
The degree of forward flexion was indicated by the
elevation angle, and lateral bending was shown by the roll
angle of the 1st lumbar vertebrae. The paired t-test was used
to evaluate the differences between pre- and post-intervention.
Analysis of variance (ANOVA) was used to detect
the effects of intervention for time (pre- vs. post training)
and group (intervention vs. non-intervention), in order to
examine the effects of training. The level of significance was
chosen as 95% for all statistical analyses