title: Physical activities at work and risk of musculoskeletal pain and its consequences: protocol for a study with objective field measures among blue-collar workers.
abstract: BACKGROUND
  Among blue-collar workers, high physical work demands are generally considered to be the main cause of musculoskeletal pain and work disability. However, current available research on this topic has been criticised for using self-reported data, cross-sectional design, insufficient adjustment for potential confounders, and inadequate follow-up on the recurrent and fluctuating pattern of musculoskeletal pain. Recent technological advances have provided possibilities for objective diurnal field measurements of physical activities and frequent follow-up on musculoskeletal pain.The main aim of this paper is to describe the background, design, methods, limitations and perspectives of the Danish Physical Activity cohort with Objective measurements (DPhacto) investigating the association between objectively measured physical activities capturing work and leisure time and frequent measurements of musculoskeletal pain among blue-collar workers.
  
  
  METHODS
  Approximately 2000 blue-collar workers are invited for the study and asked to respond to a baseline questionnaire, participate in physical tests (i.e. muscle strength, aerobic fitness, back muscle endurance and flexibility), to wear accelerometers and a heart rate monitor for four consecutive days, and finally respond to monthly text messages regarding musculoskeletal pain and quarterly questionnaires regarding the consequences of musculoskeletal pain on work activities, social activities and work ability for a one-year follow-up period.
  
  
  CONCLUSIONS
  This study will provide novel information on the association between physical activities at work and musculoskeletal pain. The study will provide valid and precise documentation about the relation between physical work activities and musculoskeletal pain and its consequences among blue-collar workers.
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Lersø Parkallé 105, 2100, Copenhagen, DK, Denmark. mbj@nrcwe.dk
authors.forename: Marie Birk
authors.initials: MB
authors.lastname: Jørgensen
authors.forename: Mette
authors.initials: M
authors.lastname: Korshøj
authors.forename: Julie
authors.initials: J
authors.lastname: Lagersted-Olsen
authors.forename: Morten
authors.initials: M
authors.lastname: Villumsen
authors.forename: Ole Steen
authors.initials: OS
authors.lastname: Mortensen
authors.forename: Jørgen
authors.initials: J
authors.lastname: Skotte
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
authors.forename: Pascal
authors.initials: P
authors.lastname: Madeleine
authors.forename: Birthe Lykke
authors.initials: BL
authors.lastname: Thomsen
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
mesh_terms: D002985:Clinical Protocols; D004185:Disability Evaluation; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D059352:Musculoskeletal Pain / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D009784:Occupational Diseases / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D012307:Risk Factors; D057566:Self Report; D011795:Surveys and Questionnaires; D014937:Work; D016526:Workload; D017132:Workplace