An ergonomics evaluation of cashier work activities at checker-unload workstations

The ergonomic suitability of the 'over-the-counter' (OTC) or 'checker unload' workstation for grocery-scanning operations has been questioned by a number of ergonomists, safety and health professionals, and retail food industry executives in the USA. There is concern that requiring cashiers to remove grocery items directly from the customer's cart for scanning exacerbates the risk of musculoskeletal disorders associated with this job. For this reason, a study was conducted to determine whether supermarket cashiers are exposed to increased biomechanical stress due to the use of checker-unload workstations for standing work. The work activities of 12 grocery cashiers from three supermarkets were recorded on videotape. Postures and movements associated with the scanning task were visually evaluated and compared with those of 10 grocery cashiers using a front-facing, customer-unload workstation examined in a previous study. The results indicate that use of the checker-unload workstation places additional stresses on the cashier beyond those imposed by customer-unload checkstands. Specifically, the task of removing groceries directly from the cart for scanning increases the frequency of long reaches, awkward shoulder postures, and lifts. These stresses can be mitigated by eliminating checker-unload operations and providing checkstands with conveyor belts for delivering groceries to the cashier. Implementing additional workstation modifications and encouraging cashiers to adopt alternative work practices also may reduce the frequencies of awkward postures and stressful motions associated with this checkstand design.