Does hallux valgus impair medial forefoot loading? A meta-analysis of plantar pressure distribution

Abstract

Background: Hallux valgus is a common foot deformity that may alter plantar pressure distribution. This study aimed to determine whether hallux valgus consistently reduces medial forefoot (hallux and medial metatarsal) load and impulse through a meta-analysis of plantar pressure data and increases central metatarsal loading. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. PubMed, Web of Science, Scopus, CINAHL, and Embase were searched for studies comparing plantar pressure distribution between hallux valgus and non-hallux valgus feet. Random-effects meta-analyses were performed using standardized mean differences (SMD) for load (force and pressure) and impulse (force and pressure-time integrals) measures in hallux, medial metatarsal, and central metatarsal regions. Risk of bias was assessed using the JBI critical appraisal checklist for analytical cross-sectional studies. Results: Twenty-one studies (3911 participants and 6407 feet) were included. In-shoe measurements showed significant reductions in hallux loading (force SMD: −0.78 [95% CI: −1.08, −0.49]; force-time integral SMD: −0.39 [−0.71, −0.07]). Platform-based measurements yielded inconsistent results. No conclusive evidence was found for reduced medial metatarsal loading or increased central metatarsal loading. Measurement modality significantly influenced results, with platform-based systems generally showing higher heterogeneity than in-shoe sensors. Nine (43%) and 12 studies (57%) had a high risk of bias on statistical analysis and confounder management, respectively. Conclusions: Hallux valgus is associated with reduced hallux loading in in-shoe measurements, but evidence for load redistribution to other forefoot regions is inconclusive. The choice of measurement modality significantly impacts results, highlighting the need for standardized assessment protocols in hallux valgus research.