Development and reliability of a device to measure medial longitudinal arch loading in individuals with foot pronation

Abstract

Objective: To develop the pronation loading (PL) device, evaluate its intra- and inter-rater reliability in single-leg stance, and investigate correlations between PL measures and gait kinetic and kinematic variables. Methods: This cross-sectional study was conducted in two stages: (1) assessment of intra- and inter-rater reliability of the PL device, and (2) investigation of correlations between PL measurements and kinetic and kinematic gait variables. Reliability was analyzed using the intraclass correlation coefficient (ICC), and measurement error was assessed using the standard error of measurement (SEM) and minimal detectable change (MDC). Associations were evaluated using Pearson’s correlation coefficient (r). Results: Intra-rater reliability showed ICC of 0.75 and 0.73, with SEM ranging from 0.04 to 0.05. Inter-rater reliability demonstrated an ICC of 0.77, an SEM of approximately 0.04, and an MDC between 0.11 and 0.13. Pronation loading measurements showed moderate correlations with peak ankle evertor external moment, knee internal rotation moment, hip internal rotation moment, and hip adductor moment during gait. Conclusion: The PL test demonstrated good reliability and significant associations with selected gait-kinetic variables, suggesting potential clinical applicability for assessing pronation-related loading during orthostatic standing. Level of evidence III; Cross-sectional (two stages)