Musculoskeletal Disorders and their Relationship to Vibration Exposure in Forklift Operators in a Paper Company, 2025

Abstract

Introduction: Forklift operators are exposed to whole-body vibration (WBV) and biomechanical loads that could increase musculoskeletal disorders (MSDs).

Objective: To analyze the association between musculoskeletal discomfort (CMDQ) and normalized daily exposure A(8) to WBV in forklift operators in a paper industry in Cotopaxi, Ecuador.

Methods: Quantitative, observational, descriptive-correlational, cross-sectional study with 54 male operators. WBV was measured with a triaxial accelerometer in the seat following ISO 2631-1:1997; A(8) was calculated. Discomfort was assessed with the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ). Descriptive statistics were applied; Spearman for correlations; Kruskal–Wallis and ANOVA with Bonferroni for comparisons; chi-square/Fisher and binary logistic regression by anatomical regions (α=0.05).

Results: The most affected regions were neck (68.5%), lower back (66.7%) and shoulders (59.3%). In exposure A(8), 38.9 % were above the limit, 25.9 % in the action zone and 35.2 % in low risk. The total CMDQ score did not correlate with A(8) (ρ = –0.100; p = 0.473), but it did correlate with age (ρ = 0.451; p = 0.001) and years of service (ρ = 0.360; p = 0.007). In the analysis by regions, only hips showed an association with WBV (OR = 4.453; 95% CI: 1.228–16.144; p = 0.016). Those over 40 years of age had higher CMDQ scores compared to 18–29 years (p < 0.001) and 30–40 years (p = 0.006).

Conclusions: There is a high prevalence of MSDs, especially in the neck, lower back and shoulders. Although A(8) was not associated with the global CMDC, WBV exposure increased the likelihood of hip discomfort and discomfort increased with age and age. Preventive measures (active breaks, vibration maintenance/isolation and exposure management) are required, prioritizing older workers/seniority.