Reliability of the Kinematic Steadiness Index during one-leg standing in subjects with recurrent low back pain.

Abstract

To assess the reliability of standing time and the Kinematic Steadiness Index (KSI) in one-leg standing compared with the Timed Up and Go (TUG) test while considering anthropometric factors in subjects with recurrent low back pain (LBP). Sixty-six individuals participated in the study. The data were collected on two different days, 1 week apart. The KSI of the core spine, using video motion-capture techniques, was based on the relative standing time and relative standstill time. The intraclass correlation coefficient (ICC_2,1) was compared for the reliability between measures. The covariates, such as age, Body Mass Index, and the Oswestry Disability Index (ODI), were analyzed for any interactions based on these measures. The standing time (t = - 1.01, p = 0.32) and the KSI (t = - 1.70, p = 0.09) were not significantly different between measures. The TUG results were not different between measures (t = 1.01, p = 0.32). The Cronbach's alpha for the standing time was 0.84, for KSI was 0.89, and for TUG was 0.76. The standing time and KSI demonstrated an interaction with age, while the TUG demonstrated an interaction with the ODI score. The KSI during one-leg standing could help to develop a practical tool to justify quantity and quality of balance outcome measures, which identify balance deficits and core spine rehabilitation strategies in subjects with recurrent LBP.