SIMULATION-BASED ESTIMATION OF SPINAL LOADING FROM SURGICAL LEAD VESTS: A MUSCULOSKELETAL MODELING STUDY OF SURGEON ERGONOMICS

Abstract

Work-related musculoskeletal disorders (WMSDs) are highly prevalent among surgeons and are often exacerbated by prolonged postures and the use of heavy radiation protective lead vests. This study used validated full-body male and female musculoskeletal models in OpenSim 4.4 to quantify thoracolumbar spine loading under representative surgical postures with and without simulated lead vests. Seventy simulations were conducted across five postures and seven vest weight configurations, modeling compressive, anterior-posterior (AP) shear, medial-lateral (ML) shear, and resultant joint reaction forces across the T1–L5 spinal segments. Simulations revealed that the L5-S1 segment consistently experienced the highest compressive forces, with peak loads reaching 1523 N in males and 1161 N in females. While AP shear forces peaked at T1–T2, exceeding 90 N, particularly during axial twisting. Vest weight placement at the sternum induced up to 28% higher spinal loads than abdominal placement, particularly during twisting and trunk-flexed postures. Although male models exhibited greater absolute forces, female models demonstrated comparable or higher normalized (% body weight) loads, underscoring the ergonomic disparities in current vest designs. Although male models exhibited greater absolute forces, female models demonstrated comparable or higher normalized (%BW) loads, underscoring ergonomic disparities in current vest designs. While loads remained below single-exposure risk thresholds, the combination of elevated spinal forces and repeated exposure poses a long-term risk of degeneration and injury. These findings highlight the need for posture-specific ergonomic interventions, sex-specific vest designs, and further in vivo validation to mitigate the occupational toll of spinal loading in surgical professionals.