The effectiveness of shoe insoles for the prevention and treatment of low back pain: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND Low back pain (LBP) is a significant public health problem in Western industrialised countries and has been reported to affect up to 80% of adults at some stage in their lives. It is associated with high health care utilisation costs, disability, work loss and restriction of social activities. An intervention of foot orthoses or insoles has been suggested to reduce the risk of developing LBP and be an effective treatment strategy for people suffering from LBP. However, despite the common usage of orthoses and insoles, there is a lack of clear guidelines for their use in relation to LBP. The aim of this review is to investigate the effectiveness of foot orthoses and insoles in the prevention and treatment of non specific LBP. METHODS A systematic search of MEDLINE, CINAHL, EMBASE and The Cochrane Library was conducted in May 2013. Two authors independently reviewed and selected relevant randomised controlled trials. Quality was evaluated using the Cochrane Collaboration Risk of Bias Tool and the Downs and Black Checklist. Meta-analysis of study data were conducted where possible. RESULTS Eleven trials were included: five trials investigated the treatment of LBP (n=293) and six trials examined the prevention of LBP (n=2379) through the use of foot orthoses or insoles. Meta-analysis showed no significant effect in favour of the foot orthoses or insoles for either the treatment trials (standardised mean difference (SMD) -0.74, CI 95%: -1.5 to 0.03) or the prevention trials (relative risk (RR) 0.78, CI 95%: 0.50 to 1.23). CONCLUSIONS There is insufficient evidence to support the use of insoles or foot orthoses as either a treatment for LBP or in the prevention of LBP. The small number, moderate methodological quality and the high heterogeneity of the available trials reduce the strength of current findings. Future research should concentrate on identification of LBP patients most suited to foot orthoses or insole treatment, as there is some evidence that trials structured along these lines have a greater effect on reducing LBP.