Foot arch morphology and lower-limb biomechanical characteristics in university students: a cross-sectional multifactorial analysis of 1,078 participants

Abstract

Abstract To examine how medial longitudinal arch morphology relates to a multidomain set of static biomechanical correlates—covering structure (forefoot/rearfoot alignment), loading/pressure behavior, arch “spring-like” function, and postural-control surrogates—as a pragmatic screening framework in university students. In this cross-sectional study, 1,078 university students (569 males, 509 females; mean age 20.18 ± 1.43 years) underwent standardized quiet-standing assessments. Arch height, hallux valgus angle, and heel valgus angle were measured using a 3D foot scanner, and plantar-pressure–derived outcomes (including arch elasticity index, AEI, and pressure recovery rate, PRR, reflecting static elastic deformation and unloading recovery behavior) were obtained using a pressure platform. Force-plate center-of-pressure (COP) time series were used to derive coordination asymmetry index (CAI; COP-based inter-limb asymmetry) and the Hurst exponent (temporal structure/long-range correlation of COP fluctuations). Left and right feet were analyzed separately for laterality-specific associations. Linear regression models evaluated continuous (arch height) and categorical (arch type; reference = normal) predictors, with sex included as a covariate; bilateral arch-height difference was modeled as a predictor of stability-related outcomes (center-of-mass displacement and mediolateral COP deviation). False discovery rate control was applied within outcome families. Arch morphology showed consistent associations with static alignment and function. Lower-arched profiles were associated with larger hallux valgus and greater heel valgus (eversion) angles, alongside lower AEI and PRR, indicating a less favorable static “spring” and unloading-recovery profile. A subset of high-arched feet also demonstrated less favorable forefoot alignment patterns, suggesting that both excessively low and excessively rigid arches may relate to forefoot mechanics, although estimates for less prevalent categories should be interpreted cautiously. Greater bilateral arch-height asymmetry was associated with larger stability-related displacements and COP deviations, and arch abnormalities/asymmetry corresponded to altered COP-derived coordination signatures (higher CAI and shifts in Hurst exponent), indicating differences in postural-control behavior under quiet standing. In university students, arch morphology and bilateral asymmetry are associated with multiple domains of static foot biomechanics, spanning alignment, pressure/elastic-function indices, and COP-derived postural-control surrogates. These findings support considering a combined screening perspective of arch type + function (AEI/PRR) + asymmetry, while emphasizing that longitudinal and interventional studies are required to determine clinical utility, actionable thresholds, and relevance to symptoms or injury outcomes.