Comparing the Effectiveness of Modified Iranian and Rigid Minerva Braces in Cervical and Thoracic Spine Movements

Background: To facilitate the fusion of the injury site for non-operative treatment or postoperative care, various braces are available to immobilize an unstable cervical spine. Among these, Minerva and Halo braces are the most effective and widely used for immobilizing unstable cervical spine injuries. The performance of cervical braces is commonly evaluated by the degree of motion restriction they provide. This study aimed to compare the function of modified Iranian and rigid Minerva braces using three-dimensional motion analysis as the standard assessment method.Methods: Twenty-nine healthy male subjects without any history of spinal pain, malformation, or surgery were recruited for this cross-sectional study. A 3D motion capture system was used to record cervical and thoracic spine flexion, extension, lateral bending, and rotation. Range of motion (ROM) was assessed under three conditions: without a brace, with the modified Iranian Minerva brace, and with the rigid Minerva brace.Results: At the cervical region, immobilization in flexion (89.03% > 87.8%) and rotation (84.85% > 83.19%) was greater with the modified Iranian Minerva, whereas extension (89.37% > 85.95%) and lateral bending (81.26% > 71.71%) were more restricted by the rigid Minerva (p > 0.05). At the thoracic region, immobilization in flexion (76.35% < 75.96%), lateral bending (46.92% > 44.5%), and extension (79.44% > 62.58%) were higher with the rigid Minerva, while rotation (53.04% > 41.21%) was more limited by the modified Iranian Minerva (p > 0.05).Conclusion: Both Minerva braces significantly reduced cervical range of motion (p < 0.05). The rigid Minerva was more effective in controlling extension and lateral bending, while the modified Iranian Minerva provided greater restriction in flexion and rotation (p < 0.05).