Assessing Workers’ Ability to Recognize Lifting Risk Factors for Low Back Pain: Investigating the Efficacy of a Simple Educational Message.

Abstract

Introduction: Participatory ergonomic approaches have been shown to be an effective method for identifying work place hazards. Since in many workplaces, expertise in ergonomics is not available, simple educational messages to identify low back injury (LBI) hazards were developed. This thesis examined lifting risk perceptions of workers and the efficacy of a simple educational message on improving their ability to recognize key LBI hazards, in particular, lifting objects on or close to the ground. Methods: 178 participants from differing sectors were shown 44 different lifting videos (representing 36 lifting scenarios). These scenarios differed in terms of factors such as lifting height origin/destination, weight, and the amount of horizontal reach. Participants were asked to rate each video, from 0-10, on how likely they believed the lifting task they just saw could eventually lead to a low back injury. One of two educational messages was then shown to the participants. These messages were crafted with the help of academic experts and knowledge translation professionals in health and safety associations. One message was used as the intervention and spoke of the risk of lifting objects from close to the floor and the other as the control and spoke of the use of back belts in industry. After reading the message, participants were shown and asked to rate the same 44 lifting videos again, but in a different order. Participant’s ratings of risk were correlated to a biomechanically-based tool (3DMatch) that estimates low back loading. Results: As lifts deviated from a waist-to-waist height, light object lift (mean Likert score = 0.421 units), ratings of risk perception increased. The highest rated tasks were the floor-to-waist stoop lift, heavy floor-to-floor lift, and the heavy floor-to-waist lift (mean Likert scores = 7.73, 7.382, and 7.107 respectively). Pre-post score differences were used to assess message efficacy. Of the 36 types of tasks, 19 significantly changed in the Lifting Height Message receiving group compared to 3 in the Back Belt Message group. The 19 changes were mainly seen in the videos that had lift origins at floor height. Participant’ risk ratings correlated positively, albeit only moderately with 3DMatch (R-value = 0.495, p<0.05). Demographically stratified correlations were also positive but were weak to moderate in strength (R-value range = 0.357 to 0.674, p<0.05). Conclusion: The results support the use of a simple message to increase conceptual awareness of the important lifting hazard of lifting objects from near the ground. This increase in recognition is the first step in the injury prevention cycle of identifying hazards, assessing risks, and controlling hazards.