the effect of three ergonomics training programs on the prevalence of low-back pain among workers of an iranian automobile factory: a randomized clinical trial

background: many workers suffer from low-back pain. type and severity of spinal complaints have relationship with work load. lack of adherence to ergonomics recommendations among the important causes of low-back pain. objective: to assess the effect of 3 ergonomics training programs on the prevalence of lowback pain among workers of an iranian automobile factory. methods: in a parallel-design 4-arm randomized clinical trial, 760 active workers of an automobile factory were studied. 503 workers were found eligible and randomized into 3 intervention groups (n=252), and a control group (n=251). the intervention groups consisted of 3 arms: 84 workers were educated by pamphlet, 84 by lectures, and 84 by workshop. nordic questionnaire was used to determine the prevalence of spinal complaint before and 1-year after the interventions. the trial is registered with the iranian randomized clinical trial registry, number irct2013061213182n2. results: out of 503 workers, 52 lost to follow-up leaving 451 workers for analyses. the prevalence of low-back pain at the baseline was not significantly different among the studied arms. 1-year after the interventions, the prevalence did not change significantly from the baseline values for the lecture and pamphlet group. however, the prevalence of lbp experienced during the last year significantly (p=0.036) decreased from 42% to 23% in participant took part in the workshop. conclusion: training of automobile factory workers in ergonomics is more effective by running workshop than giving lecture or disseminating pamphlet.