Such
supports can be applied based on a 3-point force system, an
engineering concept whereby 2 parallel forces are opposed
by a force acting in the opposite direction. Holmes et al22
examined the effects of lateral supports arranged according
to the 3-point force system, compared with 2 other arrangements
of lateral supports, in improving scoliosis in
children with spastic CP. Sitting posture was examined by
measuring spinous process angles. Significantly smaller
mean spinous process angles were reported in the 3-point
force system. Because a convenience sample was used in
which all subjects had scoliosis, generalizability is limited.
No reports of long-term effects on posture or ability to
tolerate this management were included. As well, the study
only looked at the spinous process angles in 2 dimensions,
even though scoliosis deformation is 3-dimensional. As a
result, the changes reported may not accurately reflect the
true outcome. One level IV study supports the use of lateral
supports arranged in a 3-point force system to improve
trunk alignment in children with spastic CP who have
scoliosis