The Importance of Lifting Height and Load Mass for Muscular Workload during Supermarket Stocking: Cross-Sectional Field Study

Sebastian Venge Skovlund,Markus Due Jakobsen,Rúni Bláfoss,Lars Louis Andersen,Sebastian Skals

doi:10.3390/ijerph19053030

Abstract

High physical work demands increase the risk of musculoskeletal disorders and sickness absence. Supermarket work involves a high amount of manual material handling. Identifying specific ergonomic risk factors is an important part of occupational health and safety efforts in the supermarket sector. In this cross-sectional field study among 64 supermarket workers, we used electromyography during the workday to determine the influence of lifting height and load mass on muscular workload of the low-back and neck/shoulder muscles during un-restricted manual material handling (grocery stocking). We found a significant effect of load mass, i.e., higher loads associated with higher muscular workload in the low-back and neck/shoulder muscles. We demonstrated a significant interaction between start and end position, i.e., lifts performed from ‘Low’ start positions to ‘High’ end positions demonstrated the highest low-back muscular workload, whereas ‘High’ positions were associated with increased neck/shoulder workload. In conclusion, lifting higher loads and lifting goods from low to high positions (low-back) and at high positions (neck/shoulder) are associated with higher muscular workload. These results can be used to guide highly warranted preventive initiatives to reduce the physical workload during supermarket work.

Highlights

Ergonomic risk factors in the working environment and overall high physical demands at work constitute important risk factors for the development and aggravation of musculoskeletal disorders (MSD) [1–3], sickness absence [4,5], and disability pension [6,7]
Identifying and handling ergonomic risk factors at the workplace could potentially reduce this burden and, has become a major political priority [12]. Demanding work tasks, such as manual material handling (MMH), are highly common during supermarket stocking, which may partly explain the high prevalence of MSD among supermarket workers, especially in the low-back and neck/shoulder [13–20]
In accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) reporting guidelines [44], this cross-sectional field study reports the estimates of muscular workload in relation to lifting height and load mass during grocery stocking among Danish supermarket workers (n = 75) from five different supermarket chains [45]

Summary

Introduction

Ergonomic risk factors in the working environment and overall high physical demands at work constitute important risk factors for the development and aggravation of musculoskeletal disorders (MSD) [1–3], sickness absence [4,5], and disability pension [6,7]. E.g., high work exposure to repetitive arm movement, high force exertion, kneeling, squatting, or lifting, remains highly prevalent globally [8,9] and, thereby, imposes a substantial global burden on individuals, workplaces, and socio-economics [10,11]. Identifying and handling ergonomic risk factors at the workplace could potentially reduce this burden and, has become a major political priority [12]. Demanding work tasks, such as manual material handling (MMH), are highly common during supermarket stocking, which may partly explain the high prevalence of MSD among supermarket workers, especially in the low-back and neck/shoulder [13–20]. It may be worthwhile to focus on workplace factors that dictate the physical demands needed to fulfill a given MMH task.

Methods

Discussion

Conclusion