Do rocker-sole shoes have a long-term influence on postural stability in chronic low back pain? A randomised trial

Abstract

Background People with chronic low back pain (CLBP) demonstrate greater postural instability compared to asymptomatic individuals. Rocker-sole shoes are inherently unstable and may serve as an effective balance training device. This study hypothesised that wearing rocker-sole shoes would result in long-term improvement in barefoot postural stability in people with CLBP. Methods 20 participants with CLBP were randomised to wear a rocker- or flat-soles for a minimum of two hours each day. Participants were assessed barefoot and shod, over three 40 second trials, under four posture challenging standing conditions. Primary outcome was postural stability assessed by root mean squared error of centre of pressure (CoP) displacement (CoPRMSE AP) and mean CoP velocity (CoPVELAP), both in the antero-posterior direction, using force plates. Participants’ were assessed without knowledge of group allocation at baseline, six weeks, and six months (main outcome point). Analyses were by intention-to-treat. Results At six months, data from 11 of 13(84.6%) of the rocker-sole and 5 of 7(71.4%) of the flat-sole group was available for analysis. At baseline, there was a mean increase in CoPRMSE AP(6.41[2.97]mm, p<0.01) and CoPVELAP(4.10[2.97]mm, p<0.01) in the rocker-sole group when shod compared to barefoot; there was no difference in the flat-sole group. There were no within- or between-group differences in change in CoP parameters at any time point compared to baseline i) for any barefoot standing condition ii) when assessed shod eyes-open on firm ground. Conclusions Although wearing rocker-sole shoes results in greater postural instability than flat-sole shoes, long-term use of rocker-sole shoes did not appear to influence postural stability in people with CLBP.