Ranking Stretcher and Backboard Related Paramedic Lifting Tasks Based on Their Biomechanical Demand on the Low Back

Occupational Applications We rank ordered essential paramedic lifting tasks by biomechanical exposure measures at the low back, to understand aspects of paramedic work that impose the greatest risk of musculoskeletal disorders. Specifically, stretcher raising, lowering, and loading, and scoop stretcher lifting, were ordered in terms of peak sagittal low back angles, peak low back compression and antero-posterior shear forces, estimated cumulative damage over a work shift, and the probability of being a high-risk work task. We found that scoop stretcher lifting imposed the highest peak low back angles and both compression and shear forces, while stretcher raising had the greatest estimated cumulative damage and probability of being a high-risk task. All tasks resulted in peak low back compression forces that exceeded injury risk guidelines, and all tasks were identified as high-risk based on estimated cumulative damage. These results highlight the need for interventions in the paramedic sector to reduce the resultant biomechanical exposures, prioritizing efforts towards scoop board lifting and stretcher raising. Technical Abstract Background: Paramedics experience the highest incidence of musculoskeletal disorders (MSDs) by sector. To prioritize MSD risk reduction in paramedicine, essential tasks that expose paramedics to the greatest risk of MSDs should be identified. Low back angles, compression force, antero-posterior shear force, and cumulative low back damage are biomechanical exposure variables that are associated with MSD risk. Purpose: To rank order essential paramedic lifting tasks by acute low back biomechanical exposure and cumulative low back injury risk over a work shift. Methods: Twenty active duty paramedics participated. Paramedics performed three repetitions of simulated (75 kg patient) stretcher raising, stretcher lowering, and scoop board lifting action from the head and foot ends of equipment, in addition to stretcher loading. Whole-body kinematics and ground reaction forces were collected. Kinematic data were used to calculate peak sagittal low back angles (thorax relative to pelvis), while peak low back compression and antero-posterior shear force were calculated using an inverse dynamics model. Cumulative low back damage and the probability of being a high-risk work task were calculated using the Lifting Fatigue Failure Tool. Results: Significant main effects of task were observed for all outcome measures. Scoop board lifting exposed paramedics to the highest peak biomechanical exposures, as measured by peak sagittal low back angle, and compression and antero-posterior shear forces. Stretcher raising had the highest estimated cumulative damage to the low back and probability of being a high-risk work task. Across all tasks, peak low back compression force exceeded injury risk guidelines, and all tasks were identified as high-risk based on estimated cumulative damage. Conclusion: There is a need for intervention to reduce biomechanical exposures to the low back of paramedics performing essential lifting related duties. Our data support prioritizing interventions targeting scoop board lifting and stretcher raising.