Factors Associated with Musculoskeletal Disorders Among Tractor-Operating Farmers in a Subdistrict of Roi Et Province, Thailand: A Cross-Sectional Study.

Abstract

Objective: Musculoskeletal disorders (MSDs) remain a major occupational health problem among the Thai workforce. Tractor operation enhances agricultural productivity but exposes workers to substantial ergonomic and physical risks, particularly vibration and sustained awkward postures. This cross-sectional study aimed to examine factors associated with MSDs among tractor-operating farmers in a subdistrict of Roi Et Province, Thailand.

Methods: The study was conducted among 133 tractor-operating farmers selected through proportional stratified random sampling. Data were collected using validated questionnaires assessing personal and work characteristics, Self-Ergonomics Risk Factor Assessment (SERFA), Musculoskeletal Disorders Severity and Frequency Questionnaire (MSFQ), and Subjective Workload Index (SWI). Multiple logistic regression analysis was performed, and adjusted odds ratios (ORadj) with 95% confidence intervals (95% CI) were reported at p-value < .05.

Results: The prevalence of MSDs among participants was 62.40%, and the lower back was the most affected region of disorders (60.14%). Factors associated with MSDs included tractor-driving experience <10 years (ORadj = 3.14, 95%CI: 1.18-8.30), maximum engine speed ≥2000 rpm (ORadj = 4.68, 95%CI: 1.48-14.73), years of tractor use ≥5 years (ORadj = 9.20, 95%CI: 2.67-31.69), high SWI (≥3) (ORadj = 3.56, 95%CI: 1.24-10.19), high SERFA risk level (ORadj = 5.14, 95%CI: 1.30-20.34), and perceived vibration exposure (ORadj = 3.01, 95%CI: 1.18-7.67). Frequent posture adjustment was inversely associated with MSDs (ORadj = 0.14, 95% CI: 0.04-0.49).

Conclusion: In conclusion, tractor-driving characteristics, duration of tractor use, SWI, and postural ergonomics were associated with MSDs in this tractor-operating farmer group. Perceived vibration exposure may be an important factor associated with MSDs, suggesting that engine speed management and ergonomic improvement may be considered as potential occupational health strategies for tractor-operating farmers.