Improved Ergonomic Risk Factor Assessment Using OpenSim and Inertial Measurement Units

Rapid Upper Limb Assessment (RULA) is a posture driven ergonomic risk assessment method. The RULA is simple to apply, but consequently has substantial limitations because of limited force and joint angle resolutions. Using OpenSim to understand soft tissue loading and inertial measurement units (IMUs) to measure posture represents a novel approach and provides greater resolution. We simulated the upper limb in multiple postures and under various loading conditions using OpenSim. We compared five OpenSim model output metrics to RULA risk scores. Total joint reaction forces aligned best with RULA scores. Future work will incorporate IMUs, more simulations, and analyze longitudinal injury data to model and estimate ergonomic risk.