Convex-side medial loading during early stance in thoracic adolescent idiopathic scoliosis: A pedobarographic analysis.

Abstract

BackgroundAdolescent idiopathic scoliosis (AIS) alters trunk alignment and may lead to asymmetrical lower limb loading. While gait alterations in AIS have been described, detailed convex-concave side comparisons using temporally specific pedobarographic metrics remain largely unknown. This study aimed to investigate side-specific plantar pressure asymmetries during gait in adolescents with thoracic or thoracic-dominant AIS.MethodsA cross-sectional study was conducted on adolescents with AIS recruited from a scoliosis outpatient clinic. Only thoracic or thoracic-dominant curves (Lenke Types 1-4) were included. Barefoot walking was assessed using dynamic pedobarography (Novel emed®). Convex and concave sides were defined by the direction of the major spinal curve. Plantar pressure variables included maximum force, peak pressure, force-time and pressure-time integrals, foot contact area, medial and lateral loading, center of pressure excursion index, foot progression angle, and arch index. Paired comparisons between the convex and concave sides were performed.ResultsForty-five adolescents (mean age 15.71 ± 2.22 years; 31 females) were included. The convex side demonstrated significantly greater maximum force (518.81±120.89 vs. 512.76±119.51 N, p=0.01), medial loading (151.87±57.84 vs. 146.66±57.35 N.s, p=0.04), and contact area (126.07±18.24 vs. 124.13±21.17 cm², p=0.04). Early stance revealed a reduced center of pressure excursion index (12.43±8.59 vs. 16.06 ± 9.82 %, p=0.03). No significant side-to-side differences were found in the peak pressure, total loading, foot progression angle, arch index, or pronation-supination index during the mid-to-late stance.ConclusionsAdolescents with thoracic or thoracic-dominant AIS present with a convex-side early-stance medial loading pattern compatible with pronation, though total loading remains symmetric.