Objectives-The main objective of this
study was to investigate exposure response
relations between adverse musculoskeletal
outcomes and ergonomic
exposure variables.
Methods-A cross sectional analytical
study was conducted in 11 factories from
seven sectors of manufacturing industry
in South Africa. Exposure to workplace
ergonomic stressors was assessed in
factory floor jobs (n = 46) with a simple
low technology observational model.
Repetition, force, static posture, dynamic
movement, and other job exposures were
measured. Data of adverse musculoskeletal
outcome and data on potential
confounders and effect modifiers were
obtained from subjects (n = 401) randomly
sampled from each job category
with a questionnaire given by interviewers.
Results-High prevalences of regional
musculoskeletal pain were found with
substantial variability between industries.
Sex was the only individual risk
factor (after adjustment for potential
confounders and effect modifiers) that
was significantly associated with regional
pain. Ergonomic exposures in the workplace
were significantly associated with
musculoskeletal pain of the neck and
shoulders odds ratio (OR) 5-38 (95% confidence
interval (95% CI) 1-16 to 25.0) for
repetition, and OR 3-91 (95% CI 111 to
13-7) for seated compared with standing
work; pain of the wrists and hands OR
10*2 (95% CI 139 to 75.6) for high
summed score ofdynamic postures of the
wrist).
Conclusions-This study indicates good
predictive ability to reduce ergonomic
stress with the exposure model, simple
surveillance methods, and educational
programmers in the workplace. Further
study on sampling strategies and
refinement of dimensions of ergonomic
stressors are needed.