Objectives The cross-sectional analytic study was designed to investigate the prevalence of low back pain (LBP) and risk factors for LBP among informal garment workers.

Methods There were 446 garment workers in the Northeast of Thailand who entered into this study. Data was collected by the face-to-face interview with the structured questionnaires. The LBP prevalence was estimated. The associations between LBP and studied factors were identified by the univariate analysis and multiple logistic regression analysis. Risk factors were indicated by adjusted odds ratio (OR_adj) and 95% confident interval (95% CI) at p-value <0.05.

Results Among 446 informal garment workers, most workers were female (94.84%), mean of age was 37.64 years (S. D. = 6.85) and work experience was 10.61 years (S. D. = 7.53). Most workers had the repetitive movement (69.28%, 95% CI = 64.98–73.58) and prolonged sitting of work >8 hours a day (68.16%, 95% CI = 63.82–72.50). The six month-prevalence of LBP was 44.17% (95% CI = 39.54–48.80). The univariate analysis identified factors of gender, prolonged sitting, no change posture each hour and the repetitive task significantly associated with LBP. The multiple logistic regression analysis indicated that the significantly related factors to LBP were prolonged sitting (OR_adj = 2.11, 95%CI = 1.27–3.50), no change posture each hour (OR_adj = 1.84, 95%CI = 1.11–3.07), repetitive task (OR_adj = 1.97, 95%CI = 1.18–3.30). Factor of male gender was correlated with LBP by protection (OR_adj = 0.31, 95%CI = 0.11–0.89).

Conclusions The prevalence of LBP can identify heath impact of Thai informal garment workers. The risk factors of LBP consisted of personal, work characteristics, and work behaviours. Therefore, local health care units or administrative organisations should provide occupational health service and the health surveillance program among informal garment workers. The finding risk factors are very useful to apply for prevention of new cases of LBP.