title: Baggage handler seniority and musculoskeletal symptoms: is heavy lifting in awkward positions associated with the risk of pain?
abstract: OBJECTIVE
  Heavy lifting is associated with musculoskeletal disorders but it is unclear whether it is related to acute reversible effects or to chronic effects from cumulated exposure. The aim of this study was to examine whether musculoskeletal symptoms in Danish airport baggage handlers were associated with their seniority as baggage handler, indicating chronic effects from cumulated workload.
  
  
  METHODS
  We established a group of baggage handlers employed at Copenhagen Airport during the period 1983-2012 (n=3092) and a reference group of men in other unskilled occupations with less heavy work (n=2478). Data regarding work history, lifestyle and musculoskeletal symptoms were collected using a self-administered questionnaire (response rate 70.1% among baggage handlers and 68.8% among the reference group).
  
  
  RESULTS
  The ORs of self-reported musculoskeletal symptoms during the last 12 months in the neck/upper back, lower back, shoulders, elbows, wrists, hips and knees were significantly higher in baggage handlers than in the reference group. These differences were explained by significant linear effects of baggage handler seniority for six anatomical regions. Adjustment for age, body mass index, smoking and leisure-time physical activity did not change these results. The findings were stable over age strata and among present and former baggage handlers.
  
  
  CONCLUSIONS
  The risk of musculoskeletal symptoms in six anatomical regions increased with increasing seniority as a baggage handler. This is consistent with the assumption that cumulated heavy lifting may cause chronic or long-lasting musculoskeletal symptoms. However, we cannot exclude that other factors related to baggage handler seniority may explain some of the associations.
authors.affiliation: Department of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: Stine Hvid
authors.initials: SH
authors.lastname: Bern
authors.forename: Charlotte
authors.initials: C
authors.lastname: Brauer
authors.forename: Karina Lauenborg
authors.initials: KL
authors.lastname: Møller
authors.forename: Henrik
authors.initials: H
authors.lastname: Koblauch
authors.forename: Lau Caspar
authors.initials: LC
authors.lastname: Thygesen
authors.forename: Erik Bruun
authors.initials: EB
authors.lastname: Simonsen
authors.forename: Tine
authors.initials: T
authors.lastname: Alkjær
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Bonde
authors.forename: Sigurd
authors.initials: S
authors.lastname: Mikkelsen
keywords: Epidemiology; seniority