Biokinetic gait differences between Hallux valgus patients and asymptomatic subjects

Hallux valgus (HV) is the most prevalent foot condition, associated with a decline in quality of life and a high rate of complications. Pedobarography can be a diagnostic tool, although controversies exist due to differences in measurement scales, type of capture, software, and hardware used. Deformity level differences have not been thoroughly explored. This study aimed to compare the functional parameters using pedobarography between asymptomatic subjects and HV cases.

METHODS: Cross-sectional study with a consecutive sample of 240 asymptomatic subjects and 156 HV cases, captured between 2014 and 2020 using Matscan. Time, force, and pressure parameters were analyzed by comparing 3-foot regions (heel, midfoot, and metatarsal). Maximum force and pressure were analyzed according to HV severity with 16-foot subregions.

Differences in functional parameters were observed between asymptomatic subjects and HV cases (52 mild, 52 moderate, 52 severe). Stance time was prolonged in HV, especially in severe cases. Maximum force increased in midfoot and decreased in heel and metatarsal, resulting in functional impairment. Maximum pressures and forces by subregions increased in M1(P = 0.01), and decreased in T1(P = 0.01), according to the severity of deformity, altering the intrinsic foot muscles and the windlass mechanism. Lateral metatarsal transfer was not observed.

Pedobarography can be a diagnostic tool for HV. Functional parameters are modified in HV cases (even in mild deformity) compared to asymptomatic subjects and could have predictive value. The Midfoot changes could be linked to tarsometatarsal instability and progressive collapse of the foot's arch. Early detection of functional changes can accelerate the indication of functional or surgical treatments.