Lateral Wedging of the Foot: A Scoping Review

Lateral wedges are a common intervention used to alter biomechanical function of the lower limb. Although there is evidence investigating the use and impact of lateral wedges in individuals with medial knee osteoarthritis, knowledge of how these wedges affect foot function in healthy adults is limited. Therefore, this study intends to investigate how lateral wedging affects foot function in healthy adults and, furthermore, how wedge design influences the outcome. The framework outlined by Arksey and O'Malley was used for this scoping review. To ensure methodologic quality and transparent reporting, the study adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews preferred reporting guidelines. A systematic search was conducted using MEDLINE by means of EBSCO; SPORT Discuss; CINAHL; AMED by means of OVID; and Scopus. The initial search yielded 252 articles in total; 21 studies were included in the final analysis. Significant incongruence exists in descriptions of wedge length among the 21 included studies. Thirteen studies (61%) reported using full-length wedges, five studies did not report wedge length, and only one study analyzed more than one wedge length. Ethylene vinyl acetate was the most common material, and reporting of hardness was inconsistent. A broad range of inclination angles were used, with limited explanation for why these values were selected. All but one study that analyzed ankle/subtalar joint frontal plane moments reported an increase in the external eversion moment. The review identified significant variation in the design of wedges used within this body of work and a lack of investigation into the influence of wedge design. Wedge design appears to be a secondary consideration, with very few studies examining multiple material types or wedge placements. All but one of the included studies reported a significant change in ankle/subtalar joint moments with lateral wedging. Unfortunately, further generalization was not possible because of the inconsistency and variation.