Kinematic and electromyographic assessment of manual handling on a supermarket green- grocery shelf.

Abstract.BACKGROUND: There are few epidemiological data regarding musculoskeletal disorders (MSDs) in retail industry. Biome-chanical risk assessment in ergonomics is commonly performed in retail sector using standardized protocols. However, suchprotocols have numerous limitations, such as the lack of objectivity or applicability and restrictive conditions.OBJECTIVE: The aim of this study was to analyze one of the most commonly used shelves in vegetable and fruit departmentsin order to investigate the effect of different shelf levels (i.e. with variations in height and horizontal distance) and load weightson the workers’ biomechanical load.METHODS:We investigated trunk, shoulder, elbow, hip, knee and ankle joint ROMs, as wellas the mean and peak EMG valuesof the upper limb, trunk and lower limb muscles.RESULTS: We found that shelf level has a significant effect on most of the parameters examined, whereas within this limitedrange of 6 and 8 kg, weight does not affect the biomechanical load. We also identified the shelf levels that place the least andmost strain on the musculoskeletal system.CONCLUSIONS: We therefore recommend that the height and horizontal distance be carefully considered when shelves arebeing designed. Kinematic and EMG approach may help to objectively assess shelf-related risks. Our findings are in agreementwith RNLE LI values and therefore support RNLE.Keywords: Retail sector, ergonomics, movement analysis, shelf levels, NIOSH protocol