a b s t r a c t
Background: Lateral bending is a prerequisite for various functional activities of daily life,which require combined
three-dimensional motion. Even though a number of studies have evaluated spinal kinematic changes during
lateral bending, the literature reveals a lack of data based on limb dominance. The purpose of this study was to
compare kinematic angular displacement of the spinal regions for dominant and non-dominant lateral bending
in subjects with and without recurrent low back pain.
Methods: Forty-four right hand dominant individuals with recurrent low back pain (43.1 [17.4] years) and without
low back pain (39.7 [18.7] years) participated in this study. All participants were asked to perform trunk lateral
bending to the dominant and non-dominant sideswith a bar, three times repeatedly. The outcome measures
included three-dimensional angular displacements for the three regions of the spine (upper thorax, lower thorax,
and lumbar spine).
Findings: Lumbar rotation (degrees) increased to the dominant side in the lowback pain group (9.29 [1.06]) compared
to the control group (6.20 [1.02]) with increased rotation in the upper thorax as well (t = −2.09, p =
0.04). However, the upper thorax rotation increased in the low back pain group to the non-dominant side
(t=2.08, p=0.03) and to the dominant side (t=−2.35, p=0.02). There was a group interaction with planes
(F= 5.82, p = 0.02) during lateral bending.
Interpretation: Although lower thorax motion was not different between groups, increased lumbar spine and
upper thorax rotations to the dominant side in the low back pain group were evident during lateral bending.
This directional asymmetry should be carefully monitored to understand increased lumbar rotation to the dominant
side in subjects with recurrent low back pain. The interactions between group and plane explain compensation
strategies through increased lumbar rotation to the dominant side with decreased lateral bending of the
upper thorax in subjects with recurrent low back pain.