LPB is a common problem in the working population even in a developing country. Age and gender as well as certain work-related physical and psychosocial factors influenced the prevalence of LBP but the differences between different categories of workers were small.

Background:In this study, the characteristics of menstrual cycle in shift workers employed in the pharmaceutical industry are investigated.Method:This study was conducted in a pharmaceutical industrial complex in Tehran in 2012. 406 female workers in packaging units were studied on the menstrual cycle characteristics. The studied workers were divided into two groups of shift workers and non-shift workers and were compared in terms of the frequency of menstrual disorder (short-term cycle, long-term cycle, irregular cycle and bleeding during menstrual cycle) as well as hormonal values (FSH, LH, TSH, and Prolactin).Results:The odds ratio (OR) for menstrual disorder in the shift workers was 5.54 (95% CI=2.78-11.02) compared to the non-shift workers. The mean difference of hormonal values (except prolactin) between shift workers and non-shift workers was not significant (P> 0.05).Conclusion:This study suggests that shift work may disrupt the menstrual cycle.

The study confirms the effects of physical and psychosocial factors on neck and shoulder symptoms among automobile manufacturing workers in a low to middle income country in spite of the relative youth and job insecurity of the population.

Few prospective studies in this field have been published, but all of them are related to industrialized countries. This prospective study suggests the aetiological role of job strain for LBP. The findings of this study indicate a substantial potential for disease prevention and health promotion at the workplace.