Effect of foot orthosis design on lower limb joint kinematics and kinetics during walking in flexible pes planovalgus: A systematic review and meta-analysis.

BACKGROUND: Foot orthoses are commonly used for the management of excessive foot pronation in people with pes planovalgus. However, results are inconsistent due to variability in orthosis geometrical designs. This systematic review with meta-analysis aimed to classify and investigate the effects of foot orthoses, based on their design, in terms of lower limb kinematics and kinetics in people with pes planovalgus.

METHODS: Electronic databases were searched up until August 2017. Peer-reviewed journal studies including adult participants with flexible pes planovalgus and reporting kinematics and kinetics effects of foot orthoses during walking were included and classified based on the orthosis design. Eleven studies were retained and assessed according to methodological (mean 76.1%; range [63.2%-84.2%] - high) and biomechanical (mean 71.6%; range [44.4%-100%] - moderate) qualities. Meta-analysis was performed by calculating the effect size, using standardized mean differences, between control and orthotics conditions.

FINDINGS: Meta-analysis revealed less rearfoot eversion with the use of foot orthoses including medial forefoot or both forefoot and rearfoot posting. However, no significant effect of foot orthoses with arch support and neutral rearfoot posting to control excessive foot pronation were found. In terms of kinetics, none of the foot orthoses showed effects.

INTERPRETATION: Using medial posting is the most effective foot orthotic feature to reduce the peak rearfoot eversion and to control excessive foot pronation. Nevertheless, heterogeneity between study protocols contributes to the low evidences of foot orthoses effects on kinematics and kinetics during walking in people with pes planovalgus.