Evaluation of postural stability during quiet standing, step-up and step-up with lateral perturbation in subjects with and without low back pain.

The  evaluation  of  postural  stability  during  quiet stance,  step  up  and step  up  task  with  perturbation  using posturography  could  be  useful  in treatment  and  outcome monitoring  in  chronic  low  back  pain rehabilitation  (CLBP).  The aims  of  this  study  were  twofold  and investigating  1)  differences of postural stability measures between CLBP patients and healthy participants  during  above  mentioned  tasks.  2) postural  stability characteristics between control and movement impairment groups of  CLBP  patients  on  above  tasks.  Fourteen  CLBP  and fifteen normal  individuals  participated  and  posturography outcome variables  were  obtained  during  above  tasks.  The  low  back pain  subjects  showed  significantly  different  anterior-posterior (p=0 .01) as well as medio- lateral (p=0.05) postural stability characteristics during the step up task with external perturbation, whereas quiet standing and simple step up task did not show any differences. In addition to these values, in CLBP population, the maximum COP excursion (p=0.01), standard stability (p=0.02) and the stability scores (p=0.02) were also found significant in step up with perturbation task compared to healthy participants. As the task difficulty increases CLBP patients exhibited significantly different postural stability characteristics compared to healthy participants. Conversely, sub-group analysis in CLBP patients revealed significant differences only in medio-lateral COP excursions during normal standing (p=0.005). No significant differences were observed in tasks of higher difficulties such as step up and step up task with lateral perturbation in-between patients with movement and control impairment groups of CLBP. These findings have implications for assessment and optimizing postural control interventions on functional back pain rehabilitation.