Correlation between foot pressure distribution and curve pattern in adolescent idiopathic scoliosis

Abstract

Introduction. Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional spinal deformity that impacts postural control and plantar pressure distribution, yet the relationship between specific curve patterns and foot loading remains poorly understood. Objectives: To evaluate how thoracic and lumbar curve patterns influence plantar pressure distribution in the coronal and sagittal planes. Methodology: Eighty-six adolescents with moderate AIS (Cobb angle ≈38°) were prospectively recruited and categorized into two groups: Thoracic group (n=43; Lenke type 1) and Lumbar group (n=43; Lenke type 5). Static plantar pressure was measured using the FreeMed® computerized pressure platform (Sensor Medica, Rome, Italy). Primary outcomes included percentage of body weight on the concave versus convex side (coronal plane) and forefoot versus rearfoot (sagittal plane). Main Results: A very strong positive correlation was found between curve pattern and coronal pressure distribution (R = 0.853; p < 0.001; 95% CI: 0.781–0.905), with weight consistently shifting toward the concave side. Thoracic curves demonstrated significantly greater concavity loading (54.9% ± 2.4%) compared to lumbar curves (52.5% ± 2.1%; mean difference = 2.4%; p < 0.001). A moderate correlation was observed between Cobb angle and asymmetry (R = 0.412; p = 0.023). No significant correlation was found in the sagittal plane (R = 0.064; p = 0.547). Conclusions: Curve location in AIS significantly dictates coronal plantar loading, with thoracic curves producing greater asymmetry than lumbar curves. Sagittal plane distribution remains unaffected by curve pattern. These findings support the integration of baropodometry into clinical assessment and the development of curve-specific rehabilitation protocols.