Evaluating Respiratory Effects of 3D-Printed Scoliosis Bracing in Different Physiological States

Respiratory function is a critical physiological parameter often affected in individuals using scoliosis braces due to thoracic compression. Assessing respiratory parameters, especially Vital Capacity (VC), is essential to understand how orthotic interventions influence lung function. This study investigates the impact of scoliosis brace compression on VC under varying tightness levels and physiological states. A personalized 3D-printed orthosis was designed for a subject with lumbar scoliosis and fabricated using Fused Deposition Modeling (FDM) with polypropylene material. Respiratory measurements were conducted using the BIOPAC SS11LB airflow sensor while the subject was seated in a relaxed position. VC was recorded in both fasted and postprandial states across three brace tightness levels: loose, medium, and tight. Results showed a significant reduction in VC as brace tightness increased, with the highest reduction observed under tight brace conditions. Additionally, postprandial VC values were consistently lower than fasted measurements, indicating that physiological fullness further exacerbates thoracic restriction. These findings highlight the importance of considering both orthotic compression and nutritional status in respiratory assessments of scoliosis patients. The study provides valuable insights for developing patient-specific bracing strategies that balance spinal correction with minimal respiratory compromise.