title: A prospective study of computer users: I. Study design and incidence of musculoskeletal symptoms and disorders.
abstract: BACKGROUND
  A prospective study of computer users was performed to determine the occurrence of and evaluate risk factors for neck or shoulder (N/S) and hand or arm (H/A) musculoskeletal symptoms (MSS) and disorders (MSD).
  
  
  METHODS
  Individuals (n = 632) newly hired into jobs requiring > or = 15 hr/week of computer use were followed for up to 3 years. At study entry, workstation dimensions and worker postures were measured and medical and psychosocial risk factors were assessed. Daily diaries were used to document work practices and incident MSS. Those reporting MSS were examined for specific MSD. Incidence rates of MSS and MSD were estimated with survival analysis. Cox regression models were used to evaluate associations between participant characteristics at entry and MSS and MSD.
  
  
  RESULTS
  The annual incidence of N/S MSS was 58 cases/100 person-years and of N/S MSD was 35 cases/100 person-years. The most common N/S MSD was somatic pain syndrome. The annual incidence of H/A MSS was 39 cases/100 person-years and of H/A MSD was 21 cases/100 person-years. The most common H/A disorder was deQuervain's tendonitis. Forty-six percent of N/S and 32% of H/A MSS occurred during the first month of follow-up. Gender, age, ethnicity, and prior history of N/S pain were associated with N/S MSS and MSD. Gender, prior history of H/A pain, prior computer use, and children at home were associated with either H/A MSS or MSD.
  
  
  CONCLUSIONS
  H/A and N/S MSS and MSD were common among computer users. More than 50% of computer users reported MSS during the first year after starting a new job.
authors.affiliation: Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, USA. fgerr@sph.emory.edu
authors.forename: Fredric
authors.initials: F
authors.lastname: Gerr
authors.forename: Michele
authors.initials: M
authors.lastname: Marcus
authors.forename: Cindy
authors.initials: C
authors.lastname: Ensor
authors.forename: David
authors.initials: D
authors.lastname: Kleinbaum
authors.forename: Susan
authors.initials: S
authors.lastname: Cohen
authors.forename: Alicia
authors.initials: A
authors.lastname: Edwards
authors.forename: Eileen
authors.initials: E
authors.lastname: Gentry
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Ortiz
authors.forename: Carolyn
authors.initials: C
authors.lastname: Monteilh
mesh_terms: D000328:Adult; D001132:Arm; D003201:Computers; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000453:epidemiology* / Q000209:etiology; D009333:Neck; D009784:Occupational Diseases / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D012782:Shoulder; D052256:Tendinopathy / Q000453:epidemiology / Q000209:etiology