International Journal of Industrial Ergonomics 37 (2007) 845–854 www.elsevier.com/locate/ergon
Physical workload of ﬂight attendants when pushing and pulling trolleys aboard aircraft
Ulrich Glitscha,Ã, Hans Jurgen Ottersbacha, Rolf Ellegasta, Karlheinz Schaubb, ¨ Gerhard Franzc, Matthias Jagerd ¨
a BGIA-Institute for Occupational Safety and Health, Alte HeerstraX e 111,53757 Sankt Augustin, Germany Institute of Ergonomics, Darmstadt University of Technology, PetersenstraX e 30, 64827 Darmstadt, Germany c Institution for Statutory Accident Insurance and Prevention in the Vehicle Operating Trades in Germany, Ottenser HauptstraX e 54, 22765 Hamburg, Germany d Institute for Occupational Physiology at the University of Dortmund, ArdeystraX e 67, 44139 Dortmund,Germany b
Available online 13 August 2007
Abstract The musculoskeletal loads from moving trolleys aboard aircraft were assessed by observation of trolley handling on planes and by physical workload analyses of pushing and pulling of trolleys in a laboratory set up. Trolley handling by a total of 15 female ﬂight attendants was observed on 10 short- and medium-distance ﬂights in different types ofaircraft. About 25 selected ﬂight attendants (22 females; 3 males) of ﬁve German airlines took part in the laboratory study, which comprised three-dimensional (3D) measurements of posture and hand forces during pushing and pulling of trolleys in a variety of conﬁgurations. From the on-ﬂight observations performed, between 150 and 250 trolley movements can be projected for a work shift. The greatestphysical workload is to be expected at the beginning of service: The trolleys are fully laden then, and the cabin ﬂoor can still be inclined up to 81, as the aircraft is still climbing, particularly on short-distance ﬂights. The laboratory investigation revealed that the musculoskeletal workload from pushing and pulling depends essentially on the trolley load and on the gradient of the cabinﬂoor. In addition, the degree of stressing depends signiﬁcantly on the trolley type, mode of handling and personal dexterity. The up/down force component perpendicular to the direction of motion often achieved considerable amplitudes-in some cases equal to or exceeding the force in the direction of movement. The posture analysis demonstrated that pulling forced the ﬂight attendants to adoptergonomically unfavourable postures such as pronounced ﬂexion of the back, particularly among female subjects. The highest values for ﬂexion of the back occurred while pulling the half-size trolley. The results demonstrate that female ﬂight attendants are likely to overload themselves if they frequently have to move heavily laden trolleys unaided on an inclined cabin ﬂoor. Relevance to industry On shortdistance ﬂights, ﬂight attendants have been complaining increasingly of high physical workload from manoeuvring trolleys. On the basis of the presented data airline companies may improve the trolley handling skills of their ﬂight attendances by practical trainings and may ergonomically optimize the general service procedures aboard aircrafts. r 2007 Elsevier B.V. All rights reserved.
Keywords: Pushand pull; Flight attendants; Aircraft trolleys; Musculoskeletal workload; Ergonomic recommendation
1. Introduction Passengers aboard aircraft are served with the aid of trolleys. On short- and medium-distance ﬂights, ﬂight attendants have to move what are in some cases heavy trolleys under a tight schedule along narrow and often sloping aisles. In other branches of industry as well, e.g. inÃCorresponding author. Tel.: +49 2441 231 2665; fax: +49 2441 231 2234. E-mail address: email@example.com (U. Glitsch).
0169-8141/$ - see front matter r 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.ergon.2007.07.004
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