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 aim of this study was 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 significant different anterior-posterior (p=0 .01) as well as mediolateral (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. Sub-group analysis in CLBP patients (p=0.005) shows significant differences only in medio-lateral COP excursions during normal standing. As the task difficulty increases CLBP patients exhibited significantly different postural stability characteristics compared to healthy participants. Subgroup analysis of CLBP population revealed no significant differences in tasks with higher difficulty such as step up and step up task with lateral perturbation conversely significant difference was observed during quiet standing in this study.