title: Biomechanical evaluation of supermarket cashiers before and after a redesign of the checkout counter.
abstract: An experiment was carried out on supermarket cashiers to evaluate the time, kinematic and electromyographic changes, in both sitting and standing positions, following the redesign of a checkout counter. The novelty of the prototype checkout counter is a disk wheel placed in the bagging area, which is designed to avoid the cashier having to manually push products along the bagging area. The kinematic evaluation was based on the upper limb and trunk range of motions (RoM). The electromyographic parameters assessed were mean and maximum muscular activations. Three factors were taken into account: design (before and after redesign), posture (standing or sitting) and bagging area (anterior or posterior). The results show that the RoM values are lowest after the intervention and in the standing position. Mean and maximum muscular activation patterns are similar. Differences related to the bagging area in which the goods were released also emerged. The disk wheel represents a valid aid for reducing biomechanical overload in cashiers; the standing position is biomechanically more advantageous.    Practitioner Summary: EMG and optoelectronic motion analysis systems are useful for the quantitative assessment of the effects of the redesign of the workplace biomechanical risk. Our results suggest that a disk wheel positioned in the bagging area reduces the biomechanical risk for cashiers and increases time spent resting.
authors.affiliation: Department of Occupational Medicine, INAIL, Via Fontana Candida 1, Monte Porzio Catone, Rome, 00040, Italy. f.draicchio@inail.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Draicchio
authors.forename: Martina
authors.initials: M
authors.lastname: Trebbi
authors.forename: Silvia
authors.initials: S
authors.lastname: Mari
authors.forename: Federico
authors.initials: F
authors.lastname: Forzano
authors.forename: Mariano
authors.initials: M
authors.lastname: Serrao
authors.forename: Andreas
authors.initials: A
authors.lastname: Sicklinger
authors.forename: Alessio
authors.initials: A
authors.lastname: Silvetti
authors.forename: Sergio
authors.initials: S
authors.lastname: Iavicoli
authors.forename: Alberto
authors.initials: A
authors.lastname: Ranavolo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D004576:Electromyography / Q000295:instrumentation; D004779:Environment Design; D006804:Ergonomics / Q000295:instrumentation*; D005260:Female; D006801:Humans; D018482:Muscle, Skeletal; D016272:Occupational Health; D011187:Posture; D011581:Psychological Tests; D011594:Psychometrics; D016059:Range of Motion, Articular; D013223:Statistics as Topic; D013997:Time Factors; D014584:User-Computer Interface; D017132:Workplace