title: Using observation and self-report to predict mean, 90th percentile, and cumulative low back muscle activity in heavy industry workers.
abstract: Occupational injury research depends on the ability to accurately assess workplace exposures for large numbers of workers. This study used mixed modeling to identify observed and self-reported predictors of mean, 90th percentile, and cumulative low back muscle activity to help researchers efficiently assess physical exposures in epidemiological studies. Full-shift low back electromyography (EMG) was measured for 133 worker-days in heavy industry. Additionally, full-shift, 1-min interval work-sampling observations and post-shift interviews assessed exposure to work tasks, trunk postures, and manual materials handling. Data were also collected on demographic and job variables. Regression models using observed variables predicted 31-47% of the variability in the EMG activity measures, while self-reported variables predicted 21-36%. Observation-based models performed better than self-report-based models and may provide an alternative to direct measurement of back injury risk factors.
authors.affiliation: CBF, Centre for Musculoskeletal Research, University of Gävle, SE-801 76 Gävle, Sweden. cmtrask@gmail.com
authors.forename: Catherine
authors.initials: C
authors.lastname: Trask
authors.forename: Kay
authors.initials: K
authors.lastname: Teschke
authors.forename: Jim
authors.initials: J
authors.lastname: Morrison
authors.forename: Judy
authors.initials: J
authors.lastname: Village
authors.forename: Peter
authors.initials: P
authors.lastname: Johnson
authors.forename: Mieke
authors.initials: M
authors.lastname: Koehoorn
mesh_terms: D000328:Adult; D001955:British Columbia / Q000453:epidemiology; D012090:Cumulative Trauma Disorders / Q000453:epidemiology*; D004576:Electromyography; D006801:Humans; D017770:Lifting; D017116:Low Back Pain / Q000453:epidemiology*; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D008669:Metallurgy / Q000706:statistics & numerical data*; D008875:Middle Aged; D015233:Models, Statistical; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D019370:Observation; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000706:statistics & numerical data; D011187:Posture / Q000502:physiology; D012044:Regression Analysis; D012307:Risk Factors; D057566:Self Report; D013647:Task Performance and Analysis