The Biomechanical Principles and Clinical Applications of Orthoses for Adolescent Idiopathic Scoliosis

External lumbar orthoses are widely used in the conservative treatment of spinal deformities, especially adolescent idiopathic scoliosis (AIS). This article reviews the design and construction, biomechanical mechanisms, clinical applications, and the advantages and disadvantages of these orthoses. Based on a synthesis of 14 recent studies, including rigid and flexible orthotic designs, rigid orthoses - particularly the Boston and Cheneau types - have demonstrated reliable effectiveness in preventing the progression of scoliosis, especially in AIS patients with Risser grades of 0-2. This review emphasizes that mechanical design, material properties, and patient compliance significantly influence the efficacy of stents. However, rigid orthoses offer better corrective force, but their discomfort and impact on movement limit compliance. On the contrary, soft and dynamic braces can improve wear resistance but are less effective in structural correction. Emerging smart orthoses integrate CAD/CAM, active adjustment mechanisms (such as TSA), and pressure sensors. Through personalized and adaptive support, they have the potential to bridge this gap. External lumbar orthoses remain the cornerstone of scoliosis rehabilitation. Future development should focus on integrating biomechanical accuracy, personalized modeling, and real-time feedback systems to enhance efficacy and user experience.