One possible explanation for the
lack of significant findings with respect to changes in lumbar extension following PA mobilization or
press-up exercises may be related to
the fact that the methods used to
quantify spinal motion (ie, double inclinometers and an electromagnetic
tracking system) were not sensitive
enough to detect subtle, but perhaps
clinically meaningful, changes in motion. Recently, we reported on the
use of dynamic magnetic resonance
imaging (MRI) to quantify segmental
motion of the lumbar spine during a
PA force application.
26–28 This modality appears to have an advantage
over more conventional means of
measuring spinal mobility because
segmental motion can be assessed
more precisely without the errors
typically associated with skin movement and soft tissue bulk.