Field Group - Ergonomics

A Hazard Evaluation of Musculoskeletal Risk Factors in Washington State Apple Packing Companies

This project was designed to characterize and better understand musculoskeletal risk factors among workers in the Washington apple packing warehouse industry, and to identify any controls currently in use to reduce worker injury and illness. Ergonomic assessments were conducted of workers engaged in sorting, packing, and segregating job tasks in three companies, and approximately 105 workers were interviewed. Task observations, workplace measurements, worker interviews, and videotaping were performed. There was good agreement among the variety of assessment instruments about the body sites at greatest risk of musculoskeletal injury. Repetition, static loading of neck and back, extended reaches, and awkward postures were identified as musculoskeletal risk factors. All jobs had at least one task that met the criteria of a "caution zone job" under the new Washington State Ergonomics Rule. Several jobs had at least one "hazard zone" risk factor. The report includes a variety of ergonomic risk factor reduction recommendations.

Access Report

Ergonomic Evaluation of Grocery Checkstands – Phase 1

This study of grocery checkers in a supermarket chain examined the effects of checkstand height and the alternation of scanning hand on the amount and degree of selected cashiers’ shoulder and low back muscle activity and wrist movement. Six cashiers scanned and bagged groceries for 15 minutes at each of three checkstand configurations while fitted with EMG electrodes (trapezius and erector spinae) and electrogoniometry (both wrists). Results from the data collected on a data logger indicate that scanning and bagging are largely bi-manual tasks regardless of the scanning direction, the higher checkstands increased shoulder muscle activity more so than low back muscle activity, and the high level of wrist activity puts workers in a high-risk category for the development of MSDs. This study suggests the need for more detailed measures of the low back postures of cashiers, longer periods of data collection under real-life working conditions, and a larger sample of cashiers to test.

Download Summary

Access Report

Comparison of Ergonomist, Supervisor, and Worker: Assessments of Work-Related Musculoskeletal Risk Factors

This cross-sectional study examined the ability of supervisors and workers to accurately assess the presence of musculoskeletal disease (MSD) risk factors at work sites in four different industries, examining five jobs that represented six primary categories of risk factors: posture, force, repetition, impact, lifting, and vibration. Thirty-seven supervisors and 55 workers assessed the jobs they oversee or perform through the use of a 14-item questionnaire. Their assessments were compared with detailed ergonomist job analyses to determine their accuracy in identifying the presence or absence of MSD risk factors. In assessing the absence or presence of all risk factors, agreement with the ergonomist was found 81% of the time for supervisors and 77% of the time for workers. Overall, supervisors and workers overestimated the presence of risk in assessing the jobs. Supervisors and worker assessments appear promising in recognizing risk in initial ergonomic assessments.

Download Abstract

Access Report