Investigation of Ergonomic Risk Factors and Musculoskeletal Disorder Prevalence in Cassava Processing Workers in Oyo State

This study investigates ergonomic risk factors and musculoskeletal disorder prevalence among cassava processing workers in Oyo State, South West Nigeria, providing quantitative evidence for ergonomic intervention prioritisation in a sector characterised by labour-intensive manual work. Cassava processing employs a large proportion of the agricultural labour force in South West Nigeria, predominantly women who perform prolonged peeling, grating, pressing, and frying operations in poorly designed workstations with limited mechanical assistance. This research employs an epidemiological cross-sectional design, combining ergonomic risk assessment using the Rapid Upper Limb Assessment and the Strain Index tools with a Nordic Musculoskeletal Questionnaire survey administered to two hundred and forty-three cassava processing workers across twelve processing communities. Logistic regression analysis examines associations between ergonomic risk exposure levels and musculoskeletal disorder prevalence at eight body regions, controlling for age, years of processing experience, and daily working hours. Results reveal a twelve-month musculoskeletal disorder prevalence of seventy-four percent, with the lower back, shoulder, and wrist as the most affected body regions. High-risk ergonomic exposure at the peeling stage is the strongest independent predictor of wrist and shoulder disorder prevalence in the regression analysis. Keywords: ergonomic risk, musculoskeletal disorders, cassava processing, Nordic Questionnaire, Oyo State