a b s t r a c t
Background: Motor retraining for non-specific chronic low back pain (LBP) often focuses on voluntary
postural tasks. This training, however, may not transfer to other known postural impairments, such as
automatic postural responses to external perturbations.
Objectives: To evaluate the extent current treatments of motor retraining ameliorate impaired postural
coordination when responding to a perturbation of standing balance.
Design: Planned secondary analysis of a prospectively registered (NCT01362049), randomized controlled
trial with a blinded assessor.
Method: Sixty-eight subjects with chronic, recurrent, non-specific LBP were allocated to perform a
postural response task as a secondary assessment one week before and one week after receiving either
stabilization or Movement System Impairment (MSI)-directed treatment over 6 weekly 1-h sessions plus
home exercises. For assessment, subjects completed the Oswestry disability and numeric pain rating
questionnaires and then performed a postural response task of maintaining standing balance in response
to 3 trials in each of 4 randomly presented directions of linear surface translations of the platform under
the subjects' feet. Integrated amplitudes of surface electromyography (EMG) were recorded bilaterally
from the rectus abdominis (RA), internal oblique (IO), and external oblique (EO) muscles during the
postural response task.
Results: No significant effects of treatment on EMG responses were evident. Oswestry and numeric pain
ratings decreased similarly following both treatments.
Conclusions: Stabilization and MSI-directed treatments do not affect trunk EMG responses to perturbations
of standing balance in people with LBP, suggesting current methods of motor retraining do not
sufficiently transfer to tasks of reactive postural control.