The effects of foot core exercises and minimalist footwear on foot muscle sizes, foot strength, and biomechanics: A systematic review and meta-analysis.

Abstract

Specific foot exercises and the use of minimalist shoes during running or daily life were suggested to strengthen the intrinsic foot muscles and to modify locomotion biomechanics. We aimed to review the effectiveness of these interventions to modify foot muscle sizes, foot strength, and biomechanical outcomes. PubMed, Embase, Cochrane Library and SportDiscus databases were searched (last update: 12 March 2024). Randomized controlled trials with intervention duration of four weeks or more were included. A random-effect meta-analysis was performed when at least two studies were available for an outcome. Standardized mean differences and corresponding 95 % confidence intervals were reported. The certainty of the evidence was assessed by considering risk of bias, imprecision, inconsistency, and indirectness. The evidence not summarized in the meta-analysis was synthetised. Twenty-eight trials (1399 participants) were included in the systematic review and seventeen meta-analyses were performed. From meta-analyses, minimalist shoes lead to greater strength of toes 2 to 5 (confidence interval = 0.02 to 0.76), and foot exercises resulted in lower medial longitudinal arch motion during running (confidence interval = 0.08 to 0.82). The certainty of the evidence was low to very low, mainly due to the limited number of available studies and high risk of bias. The systematic synthesis supported exercises and minimalist shoes to increase foot strength, but was conflicting for muscle sizes. The interventions occasionally modified walking and running biomechanical variables. Foot exercises and minimalist shoes may be appropriate to increase foot strength and to induce biomechanical changes during dynamic tasks.