Force Mapping of 3D-Printed Scoliosis Braces at Varying Tightness Levels Using Calibrated FSR Sensors

This study proposes a personalized, 3D-printed scoliosis brace integrated with Force-Sensitive Resistor (FSR) sensors to quantify biomechanical stress under varying clinical conditions. Using 3D scanning, CAD modeling, and Fused Deposition Modeling (FDM) with polypropylene, a patient-specific orthosis was fabricated for a subject with lumbar scoliosis. Two calibrated FSR sensors were embedded bilaterally at the lumbar-costal junction, where maximal compressive forces are typically concentrated. Data collection was performed under nine combined conditions of brace tightness (loose, medium, tight), posture (sitting, standing), and nutritional state (fasting, full), with each scenario repeated thrice over five-minute sessions. A three-way ANOVA revealed that tightness level, posture, and nutritional state each had statistically significant effects on applied force (p < 0.001), and Cohen's d values confirmed strong effect sizes across comparisons. The highest pressures occurred during tight brace use in a full, seated state. This study demonstrates the feasibility of real-time stress mapping in scoliosis braces, informing both orthotic customization and clinical guidelines for optimal brace adjustment. Future studies will extend this approach to larger patient cohorts and explore adaptive braces capable of dynamically modulating pressure based on physiological changes.