Validation of a Spine Musculoskeletal Model During Submaximal Heavy Lifting in OpenSim

Low back pain is a significant health issue with substantial societal costs. Manual handling guidelines often prove impractical in certain occupations. Musculoskeletal modeling plays a crucial role in assessing injury risks, but gaps remain in understanding spinal injuries and muscle activity under heavy loads. OpenSim software has advanced from spine-specific to full-body models, with recent enhancements to the fully articulated thoracolumbar spine model validated for small load tasks. This study aims to validate the model for submaximal heavy lifting in athletes.Sixteen young male participants performed Conventional and Romanian Deadlift tasks. Trunk muscle activity was measured experimentally and compared with model predictions using metrics like Root Mean Square Error (RMSE), Maximum Absolute Normalized Cross-Correlation (MANCC), and Pearson Correlation.The results demonstrated strong temporal similarity and high prediction accuracy, with a robust linear relationship between experimental and model data. This validates the model for submaximal lifting tasks, providing insights into athletic performance and heavy lifting scenarios.