Workstation configuration and container type influence upper limb posture in grocery bagging

Angelica E Lang; Jacquelyn M Maciukiewicz; Meghan E Vidt; Sylvain G Grenier; Clark R Dickerson

doi:10.1016/j.apergo.2018.07.012

Workstation configuration and container type influence upper limb posture in grocery bagging

Appl Ergon. 2018 Nov:73:206-213. doi: 10.1016/j.apergo.2018.07.012. Epub 2018 Jul 30.

Authors

Angelica E Lang¹, Jacquelyn M Maciukiewicz², Meghan E Vidt³, Sylvain G Grenier⁴, Clark R Dickerson⁵

Affiliations

¹ Department of Health Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
² Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
³ Department of Biomedical Engineering, The Pennsylvania State University, State College, PA, USA; Department of Physical Medicine and Rehabilitation, Penn State Milton S. Hershey College of Medicine, Hershey, PA, USA.
⁴ School of Human Kinetics, Laurentian University, Sudbury, ON, Canada.
⁵ Department of Health Sciences, University of Saskatchewan, Saskatoon, SK, Canada; Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada. Electronic address: clark.dickerson@uwaterloo.ca.

PMID: 30098637
DOI: 10.1016/j.apergo.2018.07.012

Abstract

Introduction: Repetitive movements and awkward postures are two persistent injury risk factors for grocery store cashiers. Due to the recent rise in popularity of environmentally-friendly grocery bagging options, current recommendations for cashiers are likely outdated. Correspondingly, the objective of this study was to examine the effects of cashier-specific work demands, workstation configuration, and container type on upper limb postures during typical job activities.

Methods: Fifteen experienced cashiers bagged groceries at varying combinations of workstation height (low, medium, high) and container type (reusable bins, reusable bags, plastic bags). Upper limb movement was quantified with motion capture and amplitude probability distribution functions of humeral elevation and humeral axial internal rotation were used to assess the static (10th percentile), median (50^th percentile), and peak (90^th percentile) postural demands, which were then interpreted in the context of existing postural guidelines.

Results: High workstation height and reusable bags increased right arm elevation at peak posture by 15.7° compared to the low workstation height and reusable bin combination. However, reusable bins increased internal rotation demands of the right arm by 4.3° compared to other container types. Left arm elevation and internal rotation were consistently lower than right arm angles.

Conclusion: Cashiers are encouraged to adjust the workstation to decrease the arm elevation and internal rotation required by higher workstation heights and tall containers, and to use both arms for scanning and packing, when possible, to reduce undesirable arm postures.

Keywords: Cashier; Ergonomics; Kinematics; Shoulder; Upper limb posture.

MeSH terms

Arm / physiology*
Commerce
Ergonomics
Female
Food Handling / instrumentation*
Humans
Male
Movement
Posture*
Rotation
Sex Factors
Task Performance and Analysis
Upper Extremity / physiology*
Young Adult