In the retail supermarket industry where cashiers perform repetitive, light
manual material-handling tasks when scanning and handling products, report
s of musculoskeletal disorders and discomfort are high. Ergonomics tradeoff
s exist between sitting and standing postures, which are further confounded
by the checkstand design and point-of-sale technology, such as the scanner
. A laboratory experiment study was conducted to understand the effects of
working position (sitting versus standing) and scanner type (bi-optic versu
s single window) on muscle activity, upper limb and spinal posture, and sub
jective preference of cashiers. Ten cashiers from a Dutch retailer particip
ated in the study. Cashiers exhibited lower muscle activity in the neck and
shoulders when standing and using a bi-optic scanner. Shoulder abduction w
as also less for standing conditions. In addition, all cashiers preferred u
sing the bi-optic scanner with mixed preferences for sitting (n = 6) and st
anding (n = 4). Static loading of the muscles was relatively high compared
with benchmarks, suggesting that during the task of scanning, cashiers may
not have adequate recovery time to prevent fatigue. It is recommended that
retailers integrate bi-optic scanners into standing checkstands to minimize
postural stress, fatigue and discomfort in cashiers.