There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
It has been hypothesized that individuals with low back pain (LBP) will have higher
trunk muscle activity during gait, in an attempt to limit spine motion, and that this
"guarding strategy" may be influenced by the person's psychological response to pain.
This study investigated whether the amplitude of trunk muscle activation differs between
persons with chronic LBP and healthy individuals during walking, and whether changes
in muscle activation were related to pain catastrophizing. Thirty persons with chronic
non-specific LBP, stratified into 2 groups of high (HLBP) and low (LLBP) pain catastrophizing,
were contrasted with a control group of 15 healthy individuals during walking on a
treadmill at a self-selected speed. Surface electromyographic (EMG) data were recorded
from 10 trunk muscles. The effects of Group and gait Sub-phase on EMG activation amplitudes
were assessed. The HLBP group exhibited higher activation of certain muscles throughout
the gait cycle, and reduced variability of others at specific sub-phases of gait.
A significant correlation was found between activation amplitude and pain catastrophizing
in most muscles, when controlling for gait speed and pain intensity. These data indicate
that altered trunk muscle activation is present in some patients with LBP during walking,
but does not represent a universal increase in activation for all muscles. This altered
neuromotor control is, however, more strongly associated with pain catastrophizing
than with pain intensity, and appears to represent a non-functional, maladaptive behavior,
as it alters the normal, phasic pattern of activation in certain trunk muscles.