Publication:

Occupational mechanical load and severity of knee osteoarthritis: a cross-sectional analysis

Background Knee osteoarthritis (OA) is a leading cause of pain and disability worldwide. While occupational physical activity is recognized as a risk factor for knee OA, limited evidence exists on how specific occupational mechanical loads independently influence disease severity. This study aimed to evaluate the association between cumulative occupational mechanical load and severity of knee OA using WOMAC-based outcomes. The objective of the study was to identify independent occupational mechanical load factors associated with increased severity of knee OA using WOMAC-based regression analysis.

Methods A hospital-based cross-sectional study was conducted among 200 patients with clinically and radiologically confirmed knee OA at a tertiary care center in Bangladesh. Disease severity was categorized using total WOMAC score into low, moderate, and severe groups. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of increased OA severity.

Results The majority of patients had moderate (70%) or severe (26%) WOMAC scores. On univariate analysis, increasing age, rural residence, prolonged exposure to squatting and lifting weight, higher daily walking distance. In multivariate analysis, increasing age (adjusted OR 1.18, p<0.001), longer duration of occupational squatting (adjusted OR 1.08 per year, p=0.001), and higher daily walking distance (adjusted OR 1.30 per mile/day, p=0.017) remained independent predictors of disease severity.

Conclusion Cumulative occupational mechanical load plays a significant role in determining the severity of knee osteoarthritis. Prolonged squatting and high daily walking exposure emerged as key independent occupational predictors, highlighting the importance of early occupational risk identification and targeted preventive interventions.