Pelvic alignment and plantar pressure asymmetry in adolescents with idiopathic scoliosis: a cross-sectional observational study

BACKGROUND: Pelvic alignment plays a central role in maintaining postural stability, and asymmetries in pelvic orientation may alter plantar pressure distribution. In adolescents with idiopathic scoliosis (AIS), compensatory adaptations of the pelvis and lower limbs may contribute to imbalance and asymmetrical weight bearing. The aim of this study is to investigate the association between pelvic torsion, rotation, and tilt with static and dynamic plantar pressure asymmetries in adolescents with idiopathic scoliosis. METHODS: This study included 60 adolescents with AIS aged 10-18 years. Pelvic parameters were obtained using the DIERS Formetric 4D surface topography system, and static and dynamic plantar pressure distributions were measured with the GaitScan system. Side-to-side differences in forefoot and rearfoot loading were compared using paired t-tests, and correlations between pelvic parameters and plantar pressure asymmetries were analyzed with Spearman's Correlation test (p < 0.05). RESULTS: Significant plantar pressure differences were found between the convex and concave side of curve. Forefoot loading was lower on the convex side (28.8% vs. 33.9%), whereas rearfoot loading was higher (71.6% vs. 66.6%, exact p = 0.002, effect size r = 0.48). Dynamic loading also favored the convex side (55.4% vs. 45.6%, exact p < 0.001, effect size r = 0.61). Correlations between pelvic torsion, rotation, and tilt with pressure asymmetries were weak and not significant. CONCLUSION: Adolescents with idiopathic scoliosis exhibit marked plantar pressure asymmetries, particularly under dynamic conditions.