Can foot orthoses impose different gait features based on geometrical design in healthy subjects? A systematic review and meta-analysis

Objective: Foot orthoses (FOs) are popular treatment to alleviate several abnormalities of lower extremity. FO designs might alter lower extremity biomechanics differently, but the association is not yet known. This review aimed to evaluate how different FO designs, namely FO with medial posting, lateral posting, arch support, or arch & heel support, change lower limb kinematics and kinetics during walking.

Literature survey: Electronic database search were conducted from inception to March 2019, and 25 papers passed the inclusion criteria. Two independent reviewers checked the quality using a modified Downs and Black checklist (73.7±5.5%) and a biomechanical quality checklist (71.4±17.1%). Effect sizes for differences between with- and without- FO walking were calculated, and meta-analysis was performed whenever at least two studies reported the same variable.

Results: Medial posting reduced peak ankle eversion moment. Lateral posting brought about higher peak ankle dorsiflexion and peak ankle eversion for kinematics, as well as higher peak ankle abduction moment, lower peak knee adduction moment, and higher peak mediolateral ground reaction force (GRF) for kinetics. FOs with either arch support or arch & heel support tended to decrease vertical ground reaction force, but it was not significant.

Conclusion: The findings of this review reveal that medial or lateral posting work efficiently to change foot and knee kinematics and kinetics. However, the impact force is just slightly decreased by arch-supported and heel supported FOs. Due to the small number of available studies, and heterogeneity in meta-analysis findings, further research with more standardized biomechanical approach are required.